Someone asked about the 85mm F/1.2L FD lens on 5D Mark II? Here's a snapshot with the aperture set to F/2.0. I'm using an FD adapter that has glass in it. I'm able to get a much wider aperture when using it on the GH2.
It's crazy soft at F/1.2. Dreamy and creamy, which is still a pretty cool photo. You can click on any of the images for a larger view.
You can check out the GH2 samples with this lens here: http://cheesycam.com/canon-fd-lens-85mm-f1-2-on-gh2/