I really don't think he could win in the mercedes
Not with Alonso in the Ferrari. Which I think will be fantastic next year seeing as they started working on it so early.
Looks like Sato won't be back

Lotus set to confirm Trulli & Kovi
http://www.autosport.com/news/report.php/id/80559
Would have loved to seen Sato back. He was a great driver.