FYI, I recommend steering clear of bootcampdrivers.com for this issue!!
I managed to completely break my windows installation using the November Red drivers bootcampdrivers.com
During reinstallation of windows, the boot camp installer at one point did come up and I copied the entire directory to my C:\ drive on Windows. So I think I might actually _have_ boot camp drivers now for this graphics card. If you are looking for the stock driver, that's one way to get it.
So, yeah I would also appreciate some official support here from AMD/Apple/Microsoft, anybody!?!
I am having issues getting a new Radeon 5700 XT inside external enclosure to be recognized in Windows on the macbook pro, although it works just fine in OSX and also on an intel NUC, so I know it works just not with the 5500m/apple config.