One of the things we do to keep API quality high in Silverlight is to periodically dump the complete public API set to a text file & run a diff against previous versions to see what's changed. Figured these "txref" files might be of use to someone else as well. Two caveats -- the printout for generic typenames is a little funky, and it doesn't list any APIs from mscorlib.
Since this blog server only seems to support one file per post, I'll post twice, once for Silverlight 3, and again for Silverlight 4 beta. Let me know if you find it useful.