My company makes an adapter called the "Hot Rod PL". It allows nearly any PL mount lens to be mounted and supported correctly on a micro 4/3 mount camera (G1/GH1).
The Patent Pending adapter has tripod mounts (1/4 and 3/8), 15mm mini-rod support (for mattebox and follow focus accessories) and handgrip options. The Hot Rod PL will be available in June.
Price is still TBD as I am trying to find ways to minimize costs.
There is a photo of the first unsupported prototype mount on
Prolost.com
If you send me an email, I'll let you know as soon as I have new photos/availability/pricing information.