Update, 6/10: Meh, it's a fake, according to the original poster from Secret Projects.
Nope, it's not the J-20. This very interesting picture posted on the Secret Projects forum of what's alledgedly an entirely new stealth fighter being built in China. No word yet as to whether this is the F-35 Joint Strike Fighter-like (and possibly V/STOL) jet the Chinese are rumored to be working on. So far, the poster of the image at Secret Projects has titled this two-seat fighter the JH-XX, indicating it may be a fighter-bomber. As Steve Trimble at The DEW Line notes, those engine air inlets look to be lifted from the F-35. Kind of the same way the canopy and nose section of the J-20 strongly resembles the F-22 Raptor.
Update: China Defense Blog has posted these interesting pictures and more, suggesting the jet may be the rumored JH-7B. A heavily modified version of China's JH-7 fighter bomber.