Did you install your beta data tier in Virtual PC or Virtual Server and see a high CPU load while its running? Even on real hardware, you may notice some load when nothing would appear to be going on. Someone mentioned on an internal mailing list that the data tier CPU load for a combined app and data tier installed in Virtual Server was quite high, averaging about 50-70% with most of that time being used by SQL analysis services (msmdsrv.exe).
Well, here's the answer (I didn't write the question or the answer, but I hope people find it useful). [read more]