Update:
Reveal Trailer:
Ryu, Roy, and Lucas are all currently available on the eshop. There is HEAVY traffic on the eShop, however, so it may be difficult to log in to purchase them.
ORIGINAL POST:
So...umm
this is happening:
Saddly this image is a mockup, as the actual footage was removed...but you get the point:
Apparently in the Japanese version of the game an update recently rolled out (it was not intended to go out as early as it did. The Update was meant to be held off until after their next announcement) that had the data for Roy and Ryu in it.
There were leaked videos, but Nintendo was quick to take it down via Copyright claims. It's legit (unlike the Rayman fake, actual gameplay is a LOT harder to fake than a simple character select screen) Ryu (oh, and Roy...) are coming to Smash Bros! There was even a live stream of someone playing as Ryu (they datamined/hacked the game to unlock him) but the saved broadcasts were also removed.
Update: Nintendo is doing a live Twitch stream for Smash Bros announcements right now. Will see if they officially announce these characters...
http://www.twitch.tv/nintendo
Confirmed, they just showed him on the official Smash Bros stream!
Image taken directly from stream.