If you enter the "Consumer" part from the official Japanese SFIV site, you can see this updated page for the PS3 and 360 versions.
Fei Long and Dan are pretty much officially confirmed as extra characters in the home version, as the concept art of them appears above "Extra Characters Added?".
Original Anime of each character's background story is also confirmed to be added in the home console.
The picture shows anime of Ryu and an old man that's either Gouki/Shenlong or Gen, but the fine print says "the above images are different from the ones that will be in the PS3 and 360 versions", but is Capcom trying hint at something?
On related note, the Arcade part of the SFIV homepage is updated with Rufus and Seth's pictures.
Tatsunoko VS Capcom's official site is also updated with a comic type layout & info. You can flip through the pages by the arrows below the comic.
Typo: Gouki sould be Gouken, Ryu's Master.
Either way, there's a picture an old man on the official home versions of the SFIV site.