Answers to your standard questions...
I'll start things off by answering the 2 most common questions I see posted on the various blogs:
When will we see 3rd party Extenders? We nor our OEM partners have anything public to say as of release dates. The only official comment we have is under the Media Center Extender section on the Vista website http://www.microsoft.com/windows/products/winfamily/mediacenter/default.mspx. All I can say is that we're working on it and believe you all will be happy when they are finally available.
When will we get feature X? We can't comment on features we haven't announced yet. Sorry.