I've downloaded the Orcas Beta 2 and installed Silverlight 1.1 and Express Blend Preview (August) on my main workstation at home (all inside a Virtual PC 2007 with 2GB memory allocated). The virtual harddrive files are located on a WD Raptor 10.000 RPM drive - damn, this rocks!! - Compared to my IBM T60 at work (using a encrypted 7.200 RPM drive and only 512MB allocated memory) this configuration is about 10 times faster!!
Anyway .. If you're planning to have a deeper look at Silverlight, be sure to take a look at the Silverlight Learning Guide.