Update 2: Street Fighter V has been confirmed at the Playstation Experience (don't worry, it's coming to PC—in fact, there will be cross-platform play between PC and PS4). The trailer is back online, below. Capcom also revealed about a minute of in-game footage, which you'll find below too.
Update: An accidentally early publish, it seems, as the CapcomChannel video has now been removed. See below for a few choice screencaps of the teaser.
Original: There's not much to go on at this point, save a few brief facts:
1) Street Fighter V is happening.
2) Street Fighter V is happening, and has been confirmed as "exclusive" for PC and PS4.
Release date? Nope. Feature list? Nope. Anything else beyond those two facts, and a briefly available teaser celebrating the game's competitive spirit and community? Nope.