I just installed Server 2012 until the RSAT is available. This way I have RSAT tools, WDS tools (without having to rip them out of server), and after enabling all the workstation stuff and downloading the apps from the store (I can't connect a MS account to my domain account in server), I have everything but the metro version of media player. I even installed Office 2013 on here with Windows Essentials 2012.
The big one for me was the Remote Desktops, the other big one is Hyper-V but the new one won't talk to my old Hyper-V servers anyway; others I used were DNS, DHCP, Active Directory Users & Computers, Sites & Services; but I can always RDP to one of my domain controllers for all that.
I suspect rsat being released right after MSDN/technet release on Wednesday (or at least I hope so). Indeed both the hyper-v and the clustering tools will not work with 2008R2 hyper-v hosts or clusters. For me the absence of the rsat tools won't deter me from installing Win8 on my work laptop this Wednesday, but it will be nice if they will be available soon.