Let's take a look at the MvC3 silhouette image, shall we?
Not labelled in the foreground are the trailer characters (Morrigan, Chris Redfield, Iron Man, Hulk, Wolvie, Ryu). I have written the names of the four additional confirmed characters next to their (very) likely outline (Cap, Felicia, Deadpool, Dante).
Doctor Doom and Chun Li are guesses, but both are extremely strong candidates for inclusion, and the silhouettes are quite telling. In the same parenthetical manner, I have labelled the far right image as Frank West, though I really hope he is not included in this game. I didn't like him in TvC, I've never played Dead Rising, and I don't really like the zombie-summoning, bat-wielding shtick. Similarly, after some personal debate, I marked Iron Fist. That mysterious fin (outlined in red) methinks is the popped collar of Iron Fist's costume. Not too sure on that one, though...
Anyways, the remaining two are the focus of this post. A lot of people are calling Super Skrull for that second-from-the-left. I am inclined to agree, and I think it very wise to use Super Skrull instead of using four roster slots for Mr. Fantastic and company. SS has their abilities, so it's a nice trade off between inclusion, and spreading the character love around to as many different properties as possible.
Over on the right is a character I originally had thought may be Mr. Sinister; the aforementioned fin played no small part in this, but upon further review of Sinister's character artwork, his wacky slatted cape doesn't really match. Though, as far as X-Men villains go, I believe Mag-Fuckin'-Neto will be included, but I just didn't think the image matched him either...
Some of you out there in the wild world of teh netz have suggested it is SFIV's last guy Seth. This makes more sense in terms of pose, and in Marvel/Capcom balance (8:8), but something occurred to me today: If Super Skrull is being used for popular abilities at the lowest expense of roster slots, Seth would be a good choice for the same reason. Seth is notorious for copying and using moves of others, so instead of including Dhalsim, they've got Seth using his teleport and extended punches, plus Zangief's SPD, Charlie's Sonic Boom, and Akuma's dive kick, so you can scratch those three of the inclusion list, too.
So, what do you think?!