Downloaded the beta, then RC version of Win7 last year in order to evaluate it for 64-bit use, specifically with Gerard Salonga's pc which needed to access LOTS of ram (12 Gb at present) for sample playback. Needless to say, Gerard was not only satisfied, but also enthusiastic with the performance of his Core i7 machine that I spec'ed for the job. We're planning on a dual proc machine (a la Mac Pro) but the mobo can be hard to come by.
Anyway, the start of Feb. saw a notice on a lot of sites that MS had timed the RC release to begin shutting down computers after 2 hrs. of use. This only affect users of the RC versions and not the OEM or full release of Win7. I'm peeved that MS said the software was good up to June 2010, and I expected that the shutdown would have occurred April or maybe May. Oh well...