Tommorrow Oly will release new "pro" micro 4/3 camera called E-M5. According to this article 43 Rumors | Blog | (FT5) New (precious) Olympus E-M5 info! it will have UW housing.
"There is a E-M5 Diving box coming this summer (name PT-E08). It goes 45 Meters under water, and you can use the 14-42mm II, 14-42MM IIR or MZD 9-18mm lens. Yuo can also use MF lenses like the Zuiko ED 8mm f/3.5, the ZD 50mm f/2.0. The (exteranl) Flash that comes with the E-M5 can also be used."
"There is a E-M5 Diving box coming this summer (name PT-E08). It goes 45 Meters under water, and you can use the 14-42mm II, 14-42MM IIR or MZD 9-18mm lens. Yuo can also use MF lenses like the Zuiko ED 8mm f/3.5, the ZD 50mm f/2.0. The (exteranl) Flash that comes with the E-M5 can also be used."