We already know it's more than twenty. In the same blog post, Superbot referenced both the leak (which took the roster to twenty) and the Gamescom announcements. Of course, some of the leak characters may have been removed.
Join ___Night FFAs (haven't decided on a day yet). HIgh Level FFA and 2V2 with Team AXcel. PLAY..LOSE..RAGE..PLAY..LAUGH..RESPECT, GGs.
And with your math it seems like you think there will only be 20 characters
They're not going to reveal every character, I thought that was obvious. I can guarantee right now that they're not going to announce new characters at every convention they go to. They will at the important ones (Gamescom, TGS, maybe PAX) but not the unimportant ones (Brazil, EB Games). They'll just have the game available at the majority of the conventions they're attending, and maybe they'll show off some new items, but nothing more. They're already going to about 5-7 more conventions between now and October, and they're not going to reveal 3-4, or even 1-2 characters at every convention.
What happened to every one saying "The roster is less than brawl"?
Brawl has 35, 30 would still be less than that.