I am wondering... What does everypony else see in this super crazy yet cool ship? I ask this not only because I would like to know what everyone else thinks, but also because Im new to the ship and currently just think its awesome and also very realistic (like Flutterdash).
Im also asking because this group seems to have been rather quiet lately and Im keen on stirring things up a little.

For me its one of the very few ships that I think could easily become canon. The two must have had quite a history together and they clearly now have the oportunity to spend a lot more time together in Canterlot.
I am writing two stories about these two at once, (one set around their daughters return) one of which is nearly ready to be released and is set just after Discord becomes 'reformed' in 'Keep Calm and Flutter on.' Main reason why I say anything about my own work is because that particular episode got me wondering why Celestia wanted him brought back and im keen to explore why

Although Celesita tells everypony that it was becuse his magic could be useful Im sure there were more reasons behind it. Maybe something like... She wanted him back because she loved him still.

So... What do people think makes this ship it awesome? What are the things that they would find dificult and what are the things that draw them to each other (again and again and again)?

I'll kick things off with a thought of mine. Discords pranks would certainly lighten (and cause a bit of chaos in) Celestia's otherwise rather more orderly life. While she can hold him back from doing the more evil deeds that he might find fun, others would not. She seems to be very good at forgiving him and he now seems to be willing to listen to her. Immagine how hard it would have been for Discord to accept her offer to be 'reformed', especially by the ones who had turned him into stone.
Its said that oposites attract. In Celestia and Discord's case, they certainly seem to be on the extremes.

924363 If you're looking for reasons why this ship could work, just go to Cryssy-Miu's page. Nuff said.

924371 Thanks. They seem like they might be worth a follow...

Well, I think there are a number of reasons why they fit so well together. As you said, it's realistic. Because of their past and background, it's possible they had a relationship before. If they did, than this means Celestia would have had to banish someone she once loved. It's heartbreaking, yet it's also so romantic when they get back together. Most ships can't really do that, unless the writer sets up their own sort of past head-cannon.

And of course, they always say opposites attract. Order and Chaos are polar opposites, so it's very interesting to see them come together. They have an amazing contrast together, and the author can set up great foils, if they do it right.

I also think a reason is that they're both, or supposedly, immortal. They could spend the rest of eternity together, rather than pairing Discord or Celestia with a mortal which would eventually end in death. Personally, I just think they fit perfectly together. But I can see how some would think differently.

924363 An essay ahead

The immortality. That's one of the things that got me convinced of this pairing. After all, they will both live forever so even if they weren't a couple right now, it would likely happen sooner or later because they'd spend the eternity together and learn to tolerate -> like -> love each other. You know, as you watch everyone die around you, you probably grow even more fond of those who stay by your side.

Their past acquaintanceship. Even if we need to remove the teen romance from our headcanon (unless we go for AU where Discord doesn't claim to never having had friends before), the two of them still have a history. Even a bad history is better than none because at the very least they both lived thousand years ago and thus there are things that they can reminiscent about together. Like how some things weren't invented back then. How the cities were different. How some scenery, like a mountain, is still the same. That kind of things. You know, the same way how your generation can talk about "good old times" and the kids nowadays have no clue what you're even talking about. They can be old school to the extreme together.

Their heights. This is pretty silly a thing but I prefer Celestia for Discord over every other pony because they're at least roughly the same size. Twilight, Fluttershy, Pinkie and everyone else is so damn tiny compared to Discord. Celestia is a good match.

Their strangely similar personalities. As it can be seen, Discord is fun-loving, cunning, calculating and smart. But really, so is Celestia. She has her trollestia moments in the show which obviously show that she actually wants to have fun but other ponies just can't see it. She is definitely cunning and calculating, considering how she often blatantly manipulates Twilight into doing what she needs to do, even if it is isn't obvious (though at least Celestia does it for greater good). She is definitely smart too, otherwise she couldn't have successfully ruled a country for a millenium. So Discord could really be a great partner for her, considering that their combined intellect and planning skills, not to mention their magic could accomplish so much. And his prankster side would definitely be appreciated by Celestia once he got it in check and stopped hurting ponies with it.

Opposites attract. Celestia is the epitome of order and Discord is the spirit of chaos. It's not good to have too much of one without enough of the other, so they could balance each other out. Celestia is mostly balanced already, but can't act on her more chaotic side freely because ponies judge the heck out of her (like I said in the previous part). Discord on the other hand needs someone to tame his chaos a little bit so that he can fit into the society. Celestia would be a wonderful guide to him because she already has that fun-loving side to her, lots of patience, experience in guiding someone to the right path (see, Twilight Sparkle) and a firm hold in case discipline is needed. So Celestia would act like a teacher to Discord while Discord would be an outlet for fun for Celestia.

Both can use magic and fly. Things in common, yay! They could challenge each other in these things and have fun like that. I'm sure Celestia would love to have a flying partner who wouldn't fuss about her straining her royal wings or something (of course there is Luna but one more wouldn't hurt). Then there's that magic. There's nopony else powerful enough to outrank Celestia, so she could actually learn from Discord.

Brief note as to why Celestia and not Luna, even though four out of six reasons match for her too (The ones that don't match are her personality and the opposites attract thing): Celestia is older. Discord is obviously an older guy (possibly actually older than Celestia time-wise, or perhaps he just plain looks physically older and probably has the general mental maturity to go with it) so he would probably prefer the more mature Celestia over the young and naive Luna. Just my thoughts.

I probably could think of more too, but I suppose these are the main reasons that sold this pairing for me when I was looking for someone to go with Discord

Because the sex is probably insanely awesome.

924363 Well. I call it "dyslexia". But, y'know. It's an interesting ship because the show only provides so much information on either of them. It's insinuated that Discord burned ponies alive, whereas Celestia is this stoic and mysterious regal figure. Putting them together only makes sense.

925643 Nicely simply put. Thanks.

926030 Nice thoughts. Discord might not have had any friends before, but that doesn't stop him from having had some sort of teen romance with Celestia
Also... I like the note on the heights.

And luna just doesn't have the attitude (or maturity as you say) that her sister has (That helps make DisLestia so much fun) and so I don't think she could even be considered to be shipped with Discord. I notice that in a lot of stories Luna is antagonistic toward the two having a relationship if thats any indicator.