Street Fighter IV. Thankfully, it appears that Capcom has taken the hint and will be including an eight-person multiplayer lobby for groups to observe other matches and virtually "quarter up," as it were.
SSFIV's Masahiro Taguchi let the cat out of the bag on the official Japanese blog for the game (translated by Andriasang), saying that the regular ol' Street Fighter IV did not properly convey "the feeling of players gathering together for fights." He says that the ability to create multiplayer lobbies was on the table before creating SFIV, but was scrapped in favor of the one-on-one model currently in place. As frame rate can be a particularly important issue with fighting games relative to other genres, Taguchi makes a point to dispel any worries of online stuttering while observers look on to games in progress, though admitting that the process of making this lag free was a bit of a "technical feat." We're looking forward to putting Taguchi's claims to the test in 2010 when Super Street Fighter IV lands on our consoles.