KidsWB has confirmed the new season of Pokemon in a press release, right from Toonzone:
The new Saturday line-up also will be highlighted by the recently-announced new seasons of returning favorites Yu-Gi-Oh!, with fifty-two new dueling adventures, fifty-two original episodes of the next evolution of the top-rated Pokémon franchise, along with sophomore breakout series What's New Scooby-Doo?, Ozzy & Drix and ˇMucha Lucha!
So the new season begins with 264 Try Your Best Larvitar, and the last episode will be far in Advanced Generation.

Source: http://forums.toonzone.net/showthrea...threadid=68446