This is coming from a guy named lupinko on GAF and he posted this a month ago.  The original list still had Jill and Shuma as DLC so this could be accurate.  Also Jill and Shuma are offical.  

http://www.capcom-unity.com/jgonzo/blog/2010/11/15/marvel_vs._capcom_3:_new_characters,_release_date,_and_special_edition

Seemingly thousands of these lists exist.  I don't think this deserves its own thread at all.
 
Then again, this link that you didn't post pretty much confirms it.  That roster might just be legit after all.

TASKMASTERRRRRRRRRRRRRRRRRRRRRR

AKUMA!

Like you said, there's no Mega Man on this list and Niitsuma heavily implied that there would be some version of Mega Man in the game, and he also seemed to say there were no more Darkstalkers characters beyond Felicia and Morrigan. On top of that, there's no Frank West, which is weird since he was a silhouette in the very first trailer for the game and was already in TvC.
 
It definitely looks more legit than just about any other 'leaked' list, but I'm not 100% sure it's real yet.

I thought Akuma was deconfirmed??
 
Yeah I agree with the guy above, it looks more legit than another other leaked list but can't be 100% sure.
 
I hope to god Sentinel is not on this game.  He's a fucking bitch.  Put someone better like Venom.