They released it through Tech Net should be on public Beta this Friday..
TG Daily - CES 2009: Microsoft releases Windows 7 beta
TG Daily - CES 2009: Microsoft releases Windows 7 beta
You can install it without putting in a serial and then put it in later.
Funny you mention that, the MSDN download page says to do that now; the keys won't be ready for a few days. Time to get a VM loaded up
FWIW, I got keys this morning from my MSDN Premium sub.