I have rebuild my Expression Media panel for CS5 and CS4. The panel is Flex/Flash made and includes extensions for the Bridge main window Metadata pane.
Unfortunately the new CS5/CS4 compatible panel has been submitted to Adobe Exchange (where my EM CS4-only panel is already downloadable) but not yet "approved" by Adobe.
So if any of You is interested, I will send it directly via e-mail directly, with installation instructions in english. For Windows and Mac.
I hope t have it hosted on a personal site soon, but, in the meantime, You can access the Expression Media specific tags from CS5.
Please wait 1-2 days for e-mail delivery (depends on my free time).