ahh, eula's -- you know the thing you click 'next' on to get your software installed? :-) well, for silverlight, one little note may bite some tomorrow (or today for some of you) -- well, whatever, 01 AUG 2007. that is when silverlight beta expires (and thus the initial alpha as well). so even if you have the plugin and working apps, it won't work.
now is the time...update to the silverlight release candidate. the release candidate also has an expiration, but now includes self-updating technology within the plugin. check out this post to ensure you get the latest sdk's and bits to get your samples up and running for your visitors!