I don't know if anyone has mentioned this yet. But quite a few people have been putting B4 mount lenses on their GH2s and AF100s, giving them long zooms, super wide angles, and pretty decent speed. I believe you need both an adapter and a 2x TC, but I am not completely sure on that.
Here is a B4 lens on a GH2 http://vimeo.com/20171062
B4 on an AF101 http://vimeo.com/29336988
There are more examples, just search for "B4 GH2" or "B4 AF100" or "B4 AF101". People have even figured out how to power the servo zoom and I believe they have even wired up the record button when using it with an AF100.
Here is a B4 lens on a GH2 http://vimeo.com/20171062
B4 on an AF101 http://vimeo.com/29336988
There are more examples, just search for "B4 GH2" or "B4 AF100" or "B4 AF101". People have even figured out how to power the servo zoom and I believe they have even wired up the record button when using it with an AF100.