The current 4/3 lenses will not work on the micro 4/3. You will again need an adapter-mount to fit your regular 4/3 lenses into the micro 4/3 body, and not all the features, such as metering and auto focus, may work the same way as they would if directly mounted to the body. I think you will need (yet again) a dedicated micro 4/3 lens.
You need an adapter-mount for Zuiko OM lens to fit into a 4/3 body. You need another adapter-mount to fit a Zuiko Digital 4/3 lens to fit into a micro 4/3 body.
Why can't Olympus just make a single platform and expand their current lenses. I own an E-420, and with 2x crop and lack of in-body SR/Stabilization, it's hard to find an affordable, fast normal lens that will compensate for lack of SR/Stabilization. The only thing will come in mind is Sigma 30mm f1.4. Even Tamron doesn't make one for 4/3 mounts. The Oly 25mm f2.8 is nice though, but again for a body without SR (E-420), you need to compensate.