Welp, Lupinko tweeted a message hyping something coming and making references to it going like clockw0rk and coming after Neo.
That confirms we got a Strider coming.
There was a rumor about us getting 4 new cast before a super awhile back in addition to someone finding character names in the MVC3 code with no files attached to them.
Those 2 characters were Frank West and Doc Ock. Frank has definitely been in the works for a long term if Seth comments about how long he would take to balance was true, and his silhouette on the old art that was mistakenly used on the bonus comic in the Special Edition confirms he was in the works.
That means we are getting at minimum Frank West, and Strider which means 2 more marvel characters are coming. Doc Ock could've been swapped for some other idea which means he's not a definite, but I wouldn't bet against him coming in since Seth said he was developing any new cast in MVC3 to replace tools from all of the missing old cast from MVC2. No one replaces Omega Red tools yet so he is likely a given.
All that said...who do you think the other Marvel character is? I'm betting on the return of Cyclops due to the huge moments he had before with guys like Justin Wong and since Schism is a major X-men event that will frontline him.
Hype train is go.