If you are interested and haven't grabbed the download yet, here is the linky:
http://www.microsoft.com/windows/windows-7/download.aspx
A quick side note:
The RC will expire on June 1, 2010. Starting on March 1, 2010, your PC will begin shutting down every two hours. Windows will notify you two weeks before the bi-hourly shutdowns start. To avoid interruption, you’ll need to install a non-expired version of Windows before March 1, 2010.
Once I have 64-bit installed, I'll post my findings. Enjoy the RC!