I don't want to be the first one to open discussion on this subject, so I'll let it start without me.

I'll just state the facts seen in the new episode:
The first time Discord was petrified by the Elements, he seemed to not be taking them seriously; nevertheless, he enacted a fall plan from the very moment he saw Celestia and Luna approaching him with the Elements: he planted his 'black seeds' that would imprison Celestia and Luna, would attack the Tree of Harmony and would likely have freed him.
Who knows how long later, he was freed by the CMC and then took a dive in front of the Bearers, literally painting a target on his chest so they could imprison him again.
We don't know if he knew whether his seeds were still working.

So, how many moves is Discord playing ahead his chess game? Is he good, neutral or evil?

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Discord is chaos incarnate. All that was accomplished last season was giving him an incentive to stay with the ponies and not cause wanton grief and destruction. As we've seen from this episode, however, he is not above exploiting pockets of grief and destruction. In fact, he withheld useful information for the express purpose of making Twilight's work more difficult.

Discord has no alignment. He acts in his own best interest. I don't think he even acknowledges the chess game. He goes with the flow while playing checkers all along.

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Discord's moral alignment doesn't appear on the D&D grid. He just... is. And what he is is Discord.

Spoilers follow.

Think about it: He gave the Mane Six direction when the library failed them, got Twilight to go back into the Everfree, and even explained why the calamity had taken place. And yet, at the same time, he luxuriated in the chaos, was as disrespectful as possible at every opportunity (even getting Fluttershy's name wrong,) and caused the whole mess in the first place (albeit millennia ago.)
If anything, Discord may have been acting as a caricature of himself, playing to the ponies' expectations of him even as he helped them fix the problem. Whether he's good or evil, he's definitely chaotic, and his role as mentor figure was built around building the Mane Six's strength by making them overcome adversity from both within and without.
Why would he do that? Simple. Discord doesn't want anyone to realize just how successful his redemption had been, himself included. He has a reputation to maintain, after all. Furthermore, he may have an ulterior motive: if Celestia's going to make him good, then he's going to make Equestria chaotic. Not to the point of chocolate rain and buffalerinas, but to the point where the heroes can fix their problems through their own strength, not just by firing the Rainbow Beam of Fix Everything™.

tl;dr: All according to keikaku.

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I like that. It makes a lot of sense. Kudos.

I think first and foremost Discord is selfish.

His reformation hinges on his friendship with Fluttershy. Since he wants to stay her friend, he won't do anything too bad. But Fluttershy is a very forgiving pony, so he knows he can get away with small "pranks".

EDIT: I also think asking if Discord is good or evil is the wrong question. Actions can be either good or evil. Free willed, thinking beings have the capacity for either and can continue to choose either right up until their demise. People (and ponies) may do evil but they aren't evil.

I'm not sure if destroying the Tree of Harmony would have retroactively freed Discord when he was already imprisoned, but if it would have, then it looks like Discord escaping was inevitable from the start. If Celestia hadn't ordered his reformation when she did, everyone would probably be screwed by now. Of course, the plan screwed up somewhere along the line, but it did still basically work as intended, just later.

I think his reformation is genuine, but if you ask me, Discord didn't just plan steps ahead of everyone else. He planned steps ahead of all the variables, such that his plan would still work even without him actually there. The only thing he didn't account for was changing his own mind about the whole thing.

Or maybe he had no real plan and was just winging it, and everything coincidentally worked basically in his favour. With Discord, both possibilities are likely.

I would have to say that discord has no real moral inclination to be good or evil what i mean by that is that discord him self is supposed to be the literal embodiment of chaos. Now chaos just means confusion, disorder the breakdown of the rules of society and in discords case the breaking of the laws of nature and physics.

But none of that states an intention to do harm upon anyone and while other villeins always expressed the urge to control and dominate discord simply wanted a lack of control with that being in mind i think he would willingly do things that would ether help or hinder him so long as it created the chaos he so badly wanted.

Why else would he corrupt the mane 6 instead of removing them from the equation entirely, such as sending them to the four corners of the globe or tartarus if need be and as for discord having a long term game plan i honestly don't think he has ever had one i mean it goes against the character to plan when the MO is spontaneous action.