I had to install the RTM version of SQL Server 2008 a few days ago since I'm tech reviewing a book on the product and it's rather important that the code works on the final version ;)
It was actually an interesting process. I had RC0 installed, had downloaded RC1 and was about to install it to check on some issues when I saw a note on Andy Leonard's Twitter that he was downloading RTM. So I grabbed it and overnight it came down, ready to go in the morning.
I had a VM with RC0, so I ran the uninstall. My "clean" VM got whacked with a disk problem when I copied the files without changing the path in the config file. So this was the easiest way to get moving. The uninstall went smoothly, I restarted the VM, and then started the install. It was slow, and I had to uninstall a couple pieces separately, but it went smoothly and I verified that everything was gone related to SQL Server.
I was surprised that it wanted to install the .NET 3.5 framework since that was there in RC0 and I hadn't uninstalled it.So I let that install, rebooted, and then started the SQL Server installation. I picked the base product with iFTS, tools, and BOL,a and went on with my day, installing everything in the background. A few hours later it was done (this is a VM and I wasn't checking often).
select @@version shows 10.0.1600.22
Now I need to get to work.