1) In discussion pages like this one the user doesn't see a box at the bottom of the discussion thread to enter a reply which would take them to login, but they have to search the page to spot the login option at the top and then they see the UI for replies. At some commecial sites they even let you type-in the reply text - the reply UI is always shown and usable that is (to lure you into taking part), asking you then to sign-in (e.g. via a social network account)
2) It installed ok now with SQL Server 2012 (I'll try to write a blog post with screenshots soon on that), so you can close this thread, I'll open up a separate one with comments on 1st usage experience
3) see/log some other maybe useful comments and links I had sent in this discussion thread related to video conversion via MS Transform Manager and Expression Encoder free version, video thumbnail generation etc.