One thing to watch out for here. WMDC may very likely install the 32-bit version of the Device Center even when running on 64-Bit Windows7. Rather than plugging in your WM device and letting it download the drivers
I suggest installing the 64-bit drivers first, then plug in your device.
Back in November I had issues with this - the wrong version got installed by default. This eventually led to a destabilized system and I had to rebuild my machine to correct the problem. Even after removing WMDC from my system there was a remnant left somewhere which rendered Explorer unstable. Since re-loading I have not used WM (got an iPod touch) so have not had this problem again.