Gamespot Leaks Xbox 360's New Dashboard?

Reportedly Gamespot accidentally leaked this video showing the information they received about a "May 7 update for the Xbox 360's dashboard". The movie shows that many new features are coming to the dashboard:

• 600 Windows Live Messenger contacts for your friends list
• Contact list will integrate Windows Live Messenger and show joinable session status
• Messenger contacts see what game you're playing and gamer tag
• Marketplace has own blade, skin will change independent from theme
• Users will now see what achievement they've unlocked on screen
• Low-power download mode followed by auto-shutdown
• You can watch partially downloaded video files

Hopefully this is official, and not a cruel, oh so cruel, joke. Microsoft has yet to say anything.