You're missing the point - if it's a fundamental architecture flaw that cannot be fixed, then Silverlight in its current (beta) form suffers from the same problems.

    You typically don't rush out fixes for beta 
    versions of products

You can find fixes of open-source projects as soon as they are committed.

Microsoft made a bold claim, people are curious about how they fixed Silverlight if indeed they did that. If not a new Silverlight release, than at least write some kind of blog post explaining what's different in Silverlight.

But I'd bet this is typical of Microsoft; right hand, meet left hand, please communicate :)