One thing I'd love to see announced (either at E3 or at EVO) is a Marvel vs. Capcom collection, similar to the Street Fighter 30th Anniversary Collection.
It seems like it would be pretty straight forward to include the six Capcom-made Marvel fighting games:
The Punisher might also work as a bonus inclusion (it's a beat-em-up rather than a fighting game, but it's an arcade title like the other six), but while it would help to preserve the game and make it more accessible, my concern is that it might raise the game's age rating due to the inclusion of blood and tobacco, so it might be best to leave it out.
Aside from that, they could include character profiles, artwork, online play (at least for the Marvel vs. Capcom games, though all of them having online play would probably be ideal), and behind-the-scenes information. I figure that Marvel and Capcom are already collaborating on Arcade1Up machines, so something like this seems more plausible than it used to be, at least.
A Tekken collection would also be nice, though I feel like that's less likely. (my ideal line-up for that would be Tekken 1-5 and Tag Tournament)