As we write this conclusion, Panasonic has just taken ... the G9 was lab-tested with a new lens, so it has a slight advantage over previously-tested MFT cameras in that respect.
The Olympus E-P3 is compatible with any Micro Four Thirds lens, with Olympus and Panasonic together having shipped a total of twenty five lens models at the time of writing (December 2011), or ...
The company lists about 30 lenses on its site, all using the Micro Four Thirds mount ... and a more basic 35mm f/1.4 full-frame lens. Panasonic's Lumix cameras use the L-mount system.