@Paul:Did you even watch the announcements? They said they were reopening all issues with 10+ votes. Second: Perf is a major quality problem in WPF and this is also being addressed, not to mention bringing WPF up to support today's hardware.
Drawing 10s of thousands of points in milliseconds? I'd like to see that before I believe it. Don't get me wrong... Silverlight is great, but not THAT great (unless we are talking 10s of thousands of milliseconds )