A good few months ago I wrote about SP1 for PerformancePoint and getting this working on SQL Server 2008. There were a number of attempts, and with a great deal of hacking, I got an untested environment set up, however this was not very stable and never fully tested. SP2 is due for release in December, and there are mentions of a Beta available on the web, although unavailable through MSDN, or Connect. It seems that the two promises of SP2 are Hyper-V compatibility and SQL Server 2008 integration.
A few good resources for this are as follows: