I made the leap to the "PDC release" of Windows 7 on one of my machines.
Relatively painless install.
I was curious about the User Agent, so I went to UserAgent.org and found out
Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; Media Center PC 6.0; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 1.1.4322; InfoPath.2; MS-RTC LM 8)
What a monster!