They do!
Sims2,AOE3 and GTA Vice City did that ( more to try )
You can also drag an icon of a game manually into the Games Explorer if Vista failed to recognize a certain program not as a game.
And Games Explorer does download all the Info for the Games Rating and the Cover of the Game from the net and displays this instead of only an icon.
More useful : rightclicking a game in Games-Explorer offers you to go to the support-page of the company (i.e. for downloading patches etc ) and it shows on the bottom of Games-Explorer the product-version, the manufacturer,publisher,etc..
You can sort your games by "last played" "Companynae" "Age Restrictions" etc.. Of course wirh parental controls together you can block some of the games.
Games-Explorer is one of the new features I enjoy most in Vista, no searching in the startmenu for games, no need for 25 icons on my desktop..
Also since RC1 - the built in Games show : Your computer is rated 2,7 - for this game recommended is a 1 .. so you can see how well the game will run.
I think more companies will follow this and display such infos, as it answers some questions before customers can argue with the support hotlines...
I was wondering when installing new games, if they appear in the Games Explorer window located under the start orb?