Upon further review, there may be a short-term workaround. ACR 5.2 has a companion DNG converter; I believe I'll be able to take the G10 RAW images, process them in the DNG converter, then bring them through Lightroom 2. Theoretically, that should work; hope to try it later tonight!
Ahh....the workaround was successful. Here's an early image from a street art festival in downtown Houston yesterday (LR2 processed - not straight from camera):