It certainly seems so. For a while now Gilbert has been teasing images of his characters via his blog. This isn't Double Fine Adventure as that's free and clear of publishers, thanks to Kickstarter.
SEGA actually posted a forest background with a section cut out, but Ron Gilbert's character teases are actually puzzle pieces and fit perfectly. 1+1=2. SEGA is publishing a Double Fine IP.
SEGA publishing Double Fine game
23 May 2012 | By Simon Priest