Been running Vista from RC1 in my desktop PC since September using legit Beta 2 keys. Updated to RC2 no problem. Updated to build 6000 with Beta 2 keys no problem either.
My System Properties says Windows is Activated which I thought pretty neat. However MS doesn't seem to like it when I go to Microsoft Downloads. I tried downloading Windows Defender yesterday and after WGA check it said my key is invalid -- of course. I am still exploiting the possibility of using RC2 keys in RTM with the two file swap - that's why.
My laptop PC running Vista RTM with no serial so far. Been extending it using rearm according to Bink.nu. Althought Windows is not activated, I can download from Microsoft Downloads no problem.
Just to let you know, it is strange how MS treats each installation of Vista differently depending on how you installed it. So far I haven't payed a cent for Vista and still trialling until I buy the OEM version with a new PC.
Something I noticed just today morning is that Microsoft is also playing dirty with Microsoft Updates. So far I have disabled automatical installation of Microsoft Updates and I made sure I skip "Validation Update". Today morning it seemed to have installed without notification.