Project Manager Shizowa promises on his SF4 development blog that the character's section of the official Street Fighter 4 website will be updated with new characters on February 8th.
A rough translation of Shizowa's post gives us:
" However, at last!
February 8, the official site will update [Character]!
For details, but I can not tell you yet, and ○ ○ ○ ○ ○ ○ ○,
I planned out a lot, so I encourage them to come check please! "
Hopefully some new characters will be revealed this friday, after all we are gonna be only a week away from AOU, so probably we will see more than one character added to the profiles section.
We will keep you posted.
Source: SF4 Dev Blog