Here is available the SP2 CTP for SQL Server 2005.
The what’s new document explain that there is an improvement in many-to-many dimension relationships calculations. I will try to evaluate the performance improvement, but unfortunately I’m in the middle of a busy timeframe (next week I will be in Seattle for SQL Pass – if someone want to exchange some opinion face-to-face here, let’s contact me directly).
If someone get hands-on experience on many-to-many performance changes, please let me know.