The problem with a big corporation is that it sometimes feels like you're dealing with multiple companies.
There are several places to get Windows 7. When I got the beta, I followed a link that a friend gave me, which took me to technet.microsoft.com, and from there, I downloaded the beta and got my key. Then later, I needed to get some additional developer resources that I couldn't get from the TechNet download, so I joined the ecosystem program at Microsoft's Connect website, which lets people download Ult, Prem, debug versions of Windows 7, developer kits, etc. Then for the RC, I didn't think too much about where to get it, and since I happened to be on the MSDN main page (outside of the subscription area) for other reasons at the time, and it was advertising the RC download, I got my RC from there.
So I ended up with three RTM announcements in my inbox: one from TN (non-sub), one from MSDN (non-sub), and one with a generic header which I assume was from Connect.
And there are still other ways to get Windows 7, like through a MSDN sub or a TechNet sub. The vanilla downloads from TechNet (non-sub) and MSDN (non-sub) all use the same small set of keys for everyone (so you can Google the key they gave and find it on thousands of sites). The Connect website and MSDN/TechNet subs, OTOH, generate unique beta/RC keys that you and only you have. It's a huge mess how MSFT did the beta/RCs, with at least 5 different official places to download (6 if you count the invite-only beta program at Connect), at least 3 separate key generation systems, and, in my case, at least 3 e-mails telling me about RTM.