I doubt they’d be purchasable out of order. I mean, there’s an ongoing storyline — why would you want to buy them out of order?

That’s even bumuming you’d have to pay for it. Ep2 was well into development when they were going back and forth about whether to charge for it or not. Now, given the reasoning (in the blog entry and elsewhere) for why they decided to charge for it, I think it’s likely they will charge again, as I don’t see those reasons changing.

But in any case, it is WAY too early to be discussing this. Ep2 isn’t even a week old yet, and they’re focused on fixing problems more than creating that future (near as I know — there are over 300 bug reports waiting to be processed).