Wookieepedia has a listing of 25 (not the previously promised 22) episodes for Season One, ending in April. Since it is after all a Wiki, treat it as a rumor not as confirmed fact. Even more incredibly, Wikipedia’s entry on the show had a listing of 45 episodes, which would include a huge chunk of Season Two but that seems to have been edited out of the entry.
TFN has posted an interview with Henry Gilroy and Dave Filoni. Read about how Lucas considers CW canon, the lighter side of Anakin, trying to save Plo Koon, Ahsoka’s future, etc..