Not sure when they where added, The earliest I've found is Sunday, but nobody's mentioned it yet (as far as I can see). You reviews also get added to the page found on Tuesday [ http://blogoscoped.com/archive/2006-12-19.html#n48]
Just go to a model and click ratings and reviews.
Model [ http://sketchup.google.com/3dwarehouse/details?mid=91a55991c78fb72486ee580772ac6d53]
Reviews Page [ http://sketchup.google.com/3dwarehouse/ratings?mid=183769f8895b334dd32cf18b1993a141]

Some weeks ago there was an update of 3D Warehouse, but I don't remember if this was already there...

but the WII controler model is really nice :)

Are you refering to this [ http://blogoscoped.com/archive/2006-09-11-n11.html] ?
The only updates here are how "complex" the models are and a location if there is one, I think the ratings have been launched with in the last week.

You're right, so good pick MISTER Mrrix32 ^^