UPDATE 6/2/2011: According to an update on Capcom's community site, the publisher is apparently planning to patch out the offline roster restriction either at or shortly after launching the game. This is a big, big step in the right direction.
Were you looking forward to getting the PC version of Super Street Fighter IV: Arcade Edition? You might want to rethink your choice.
Yang and Yun will have to go on being annoying without me.
The above link goes to Capcom's community site, where the publisher confirms that the upcoming PC version of SSF4:AE will disappointingly use the notoriously problematic Games For Windows Live software for online multiplayer (rather than the superior Steamworks), and even more frustratingly--if you're not continuously connected to the Internet, you will only be able to use 15 of the game's total roster of 39 characters.
If you had planned to play AE on the go, such as on your laptop, in areas that may have spotty or no Internet, it sounds like you're basically hosed, here. It's also frankly hard not to see this as the publisher punishing customers who will actually buy the game legitimately...because you just know the offline restriction will be worked around by pirates, who will get all the benefits of a true SSF4AE experience, and won't even be out the 40 bucks.
This is frustrating to me personally both as a PC game player and as a longtime fighting game player who was probably going to finally give in and start up Street Fighter IV with AE. No such luck. I don't know about you guys, but until Capcom provides clarification (along the lines of "hey guys, actually, you WON'T be restricted to only 15 characters offline"), I won't be touching the PC version of this game with a 10-foot pole.