The official site for Street Fighter IV's mobile version may just have given us a look at the line-up for the game, potentially revealing—in teeny, tiny mobile phone resolution—the remaining unrevealed fighters and a possible character count. In addition to the sixteen already confirmed world warriors appearing in SFIV—twelve of whom are Street Fighter II vets—six other character slots may have been filled. In addition to those 22 character profiles, we see what looks like Vega (aka Claw) holding down a spot sans mask.
It doesn't appear from our squinting that we'll be seeing any Alpha or Street Fighter III mainstays—unless that's Juli/Juni and Rolento is sporting spectacles—but we may be interpreting some of these incorrectly. Also, these could simply be placeholder character shots and strictly limited to the mobile version of SFIV, so don't take them as gospel—especially since they're about 25x25 pixels each. Consider this rumour for now and give us your best guesses in the comments.
Street Fighter IV Mobile [Capcom Japan - thanks awhiteshad0w!]