Knowing the way Japanese teams seem to work, with queer isolation from one another at times (and one team leader approaching another seemingly with a white flag, diplomats, and tribute wagon in tow), my thought is:
* MVC3 team doesn't communicate much with SFIV team.
* SFIV team begins experimenting with online infrastructure in Super SFIV without pressure of primary game development.
* MVC3 team remains largely focused purely on content creation and character balancing, which to be fair had to be a nightmare.
* MVC3 team only vaguely pays attention to development of Super SFIV.
* Capcom PR agents start going back to MVC3 team, telling them how public wants all these features from the Street Fighter team's game in Marvel.
* MVC3 team groggily waves from behind workstations that they'll check into it sometime, thinking it is not their team's problem, their game design document didn't have that stuff in it.
Personally, I think odds are favorable that we'll get features such as a spectator mode, and a replay system, patched in MVC3 after the game ships, and the team slows down to begin addressing issues, watch for patchable glitches, and finish off DLC characters. Not 100% for sure, but at least 70%