I'm the principal developer on Project Tuva, and I've posted a bit on my blog about the technical details of the project, in case anyone's interested: http://blog.endquote.com/post/144450114/project-tuva-post-mortem

Regarding all of the Silverlight criticism -- yes, the videos could have just been posted in ogg vorbis or something to make everyone happy, but the Silverlight app adds many additional features in support of learning. Think of it as the bonus content on the DVD release. It's actually pretty cool. Silverlight isn't evil, and as someone who's very familiar with both Flash and Silverlight, I can tell you that badly-behaved Flash apps are more likely to make your system unstable than Silverlight apps will.