Sorry for a bit more downtime (well, 13 minutes to be more precise). Switched the site over to the release version of Windows Server 2008 (Windows Web Server 2008 x86).
Overall, pretty painless...just install Windows, install the Web Server role, enable a bunch of Role Services, then add a few Features (like Windows PowerShell). Finally, install Windows SharePoint Services 3.0 SP1 & do a minimal amount of configuration using the Central Admin tool. Create a dummy site, then go over to the existing standalone server, change my internal DNS settings, kick off the site backup, and then kick off the site restore on the new server. By the time the DNS changes had replicated, everything was done.
Except I forgot the HTTP SPN again, and so had to set that and change the ISA configuration to point to sharepoint4 instead of sharepoint3. Oh, and I fixed the SSL stuff, so https://www.ntldr.com/ will now work (assuming you've installed & trust my root CA).
Now playing: Pete Samples – Yours Makes Mine – 04 Between Exhales