I have been trying to download the Windows 7 Support Drivers for the last few days, with no success (for a new 15in MBP (not retina). It looks like it loads about 1/2 way, then stops, asks you to put a CD in to burn it, then it will not burn and essentially stops working. Apple support said they have not loaded the updated drivers to the server yet (I wish that message would come up instead of a stalled set-up). The guy told me to try after Monday night. I did install Windows, just waiting for the drivers now.
I had a slight problem like that. My download stopped halfway through and wouldn't budge.
Make sure that you uncheck "Create Windows 7 install disk" and "Install Windows 7". This makes it show it downloads the drivers separately from everything else, and should give you an option of where to download it.