they won't put a large amount of new characters, last time they did that was Street Fighter 3 and Street Fighter EX, both of those games wasn't as popular. Players want to play with their favorite characters and replacing them with completely new characters will alienate quite a lot of fans. Street Fighter 3 was initially planned to come out without Ryu and Ken, they were added in due to fan demand. So the most popular characters will remain.

Instead they settle with tweaking old characters. Nash, M. Bison, Chun Li and Birdie all receive a lot of changes. The work involved here is not much less than designing completely new characters.

Street Fighter 4 also almost the same, they start with 12 old characters and 4 new characters, not counting bosses and hidden characters.

Anyway, any Asia PS+ members already receives email for their Beta? They said email going to be send out starting the 21st.