from an interview with Panasonic on dpreview.com, a few more snippets of insights into the new Micro Four Thirds system which dominated Photokina 2008.
Forthcoming cameras will eventually have HD movie mode but unlike the case with dSLRs and their fixed focus, fixed aperture movie mode, these new cameras will allow continuous contrast-detect AF and exposure adjustment via adjustable aperture, thus more video camera-like in functionality.
It is unlikely that dSLRs with mirrors will be able to have live contrast-detect AF and aperture adjustments during movies without substantial re-engineering of their lenses. (This is my assumption from my readings on this matter).
Backward compatibility with contrast detect AF and older Four Thirds lenses is unlikely to be resolved EXCEPT by firmware upgrades for those lenses which are contrast-AF compatible with the E420 and later dSLRs.