Here is the link
https://windows7upgradeoption.com/Landing.aspx
Its "limited quantities" for the special pricing whatever that means. Site is supposed to go live at 1am.
I also have the RC candidate installed to test, it works fine. No annoying Vista issues and some soft users will complain about. The word on the RC candidate is that it will stop working when w7 is released. You cannot upgrade the RC copy, only XP and Vista.
The shafty part is Europe gets and E version with no IE. That pricing is for full versions of the software since they cannot upgrade to non IE - that kind of blows.