I've finally gotten a few minutes to play with Longhorn - I've downloaded all 3 public betas and never installed any of them, and figured that the release of RC0 was an indicator that the time to prep for release was now.
For some reason trying to download anything from Technet causes my IE to flail around trying to do something with my Live passport ID, and it fails, so I had to use Firefox to download it...I thought that was weird.
BUT, I did get it downloaded, and quick. Then I spun up a new VM, mounted the ISO and was off. A Server Core install was done in about 15 minutes! (Maybe less - I went to get a coffee, came back and it was done)
Then I sat down and tried to figure out what do with it. It is in a sandbox, so I'll need a DC, so that was where I started. A quick google later had me directions for the installation, and 20 minutes later I have my brand new longhorn domain up and running.
Important note - server core includes notepad! I was trying to create the unattend.txt file with echo>file and then EDLIN and just found another notice that notepad was added to server core waaaay back in beta 2 days.
Now for the very initial impressions.
Fast.
Surprising - server core actually has a gui! I was expecting the linux command prompt experience, instead there is familiar vista-ish logon screen, then an empty desktop and a familiar CMD window. You can access task manager and open new windows, and gui apps will run - the VMWare tools for example went on flawlessly. This is probably common knowledge, but shocked the hell out of me when I saw it. I love it.
I eagerly await the final release so I can migrate my DCs.