Since carrying out the in-place upgrade using Windows 7 x64 SP1 media I've discovered a couple of issues.
Firstly, certain windows features are turned off for some reason. The main three are Internet Explorer 8, .Net 3.5 and Windows Search. It's a simple matter to turn them back on but it's worth noting as the absence of these things can cause other problems. In my case, the absence of .Net 3.5 caused the Intel graphics tray application to stop working.
Secondly, the RSAT tools are missing and the current release of the RSAT tools is for pre-SP1 only. Microsoft have documented this at http://support.microsoft.com/kb/2517239/en-us and are planning to release an updated version of the tool at some point in the future. There's a workaround at http://www.msfn.org/board/index.php?showtopic=150221 but given the limited success of the recent pending.xml workaround, I'll wait for the official release!
UPDATE ON 13-Apr-2011: The RSAT tools for SP1 have been released and are available at http://www.microsoft.com/downloads/en/details.aspx?FamilyID=7d2f6ad7-656b-4313-a005-4e344e43997d&displaylang=en