Remember folks, at this time this is just a rumor:
Fujifilm is moving to M4/3rds with a new body that will have an EXR sensor inside. The official announcement about Fuji's joining to the M4/3 system will be made a few weeks before the camera announcement itself next PMA season (Jan/Feb 2010).
The new camera body --tentatively named: Micro-S10EXR (MS10), will have a 4/3rd 12MP EXR sensor, that shares a lot of its technologies and modes with current Fuji EXR compacts, just in a much larger sensor area and pixel size. The MS10 will be intermediate in form factor between the E-P1 and the GH1. It will have sensor shift stabilization, a substantial hand grip, tilt & swivel (similar in design to D5000), and a built-in EVF that is more akin to the EVF's of Fuji compacts than to that of the GH1. The entire body is made by Fuji or designed for them specially to fit the MS10 (ie nothing is cloned from any of the current M4/3 bodies except for the mount & standards of course). For lenses however, the MS10 will have to use any of the available lens options for M4/3. The camera will be marketed with EXR sensor as its main selling point.
I would like also to remind you about this post, where an Olympus representative gave an interesting answer to a potential Fuji involvement in the m4/3 market.
