Is this it? 

The extensions are designed to help developers write fully-fledged Xbox Live Arcade titles using the XNA managed framework, exposing functionality that is hidden to the public out of necessity - such as achievements and TrueSkill rankings - and allowing developers to use the XDK's debugging tools and Xbox 360 developer units in lieu of regular retail machines.

Not to say thats not cool or anything, but I really don't know if I quite understand what is being announced.    

The extension is structured in Visual Studio as a third profile alongside Xbox 360 and Windows, with a project converter available for games that have already begun life on other platforms. The leaderboard, rich presence and Achievement functionality is encapsulated in several new types, while other Xbox Live features are exposed through expansions of existing types.

I assume there will be sometype of gatekeeper at MS who will allow certain shops to utilize this if their game is worthy?  I don't quite understand how it is going to work.  I would assume that any of the small game I have written won't be getting achievments (I really don't want them to have them).  I would think that it would dilute the "percieved quality" of someone's achiehment score.  Is this just a way for MS to allow what it considers "good" games to graduate from the confines of the personal XNA framework to the larger some larger "arcade library" for everyone to use?  (wouldn't that really be the big announcement, or is that what everyone is going to assume is incomming?)

It will be interesting to see what discussion comes of this, I am not sure I have grep'd everything I need to for understanding what the announcement really means for smalltime XNA developers (or if it is really just geared at the shops trying to break through to the XBLA Arcade Market).