The RTM version of Server 2008 R2 is available for download on TechNet. Make sure you go to the "Top Downloads" section and use the Akamai plug-in to download the iso and not File Transfer Manager.
Horray for R2. I will be evaluating it to see how it goes. Thanks for posting this - I was hoping someone would've noticed this as I just saw it tonight.
This will successfully prepare a Windows Server 2008 upgrade for Windows Server 2008 R2 by updating the forest and domain schema on a PDC/GCS (Primary Domain Controller / Global Catalog Server)