Just wait till a few days after release maybe be some used/returned ones around from people who havent got a big enough space. Seems strange you ordered pretty close to when the pre-orders went up, does seem weird perhaps they made a mistake in sending you that email.
Or the rumour that the UK launch allocation is pitiful is true; either way I'm not fussed as I'm in the US until the 19th anyway!
Some review scores shamelessly stolen from elsewhere:
IGN:
Kinect Sports 8.0
Dance Central 8.0
Kinect 7.5
Sonic Free Riders 7.5
Kinectimals 7.0
Kinect Adventures 6.5
Joy Ride 6.0
GameInformer:
Dance Central 8.75
Kinect 8.0
Kinect Sports 8.0
Kinectimals 8.0
Kinect Adventures 7.5
Joy Ride 7.0
Sonic Free Riders 5.75
GameTrailers:
Kinectimals 8.5
Kinect Adventures 6.6
Kinect Sports 6.4
Joystiq:
Kinect Sports 4/5
Kinectimals 4/5
Dance Central 4/5
Your Shape Fitness Evolved 3/5
Joy Ride 2.5/5
1UP:
Dance Central A-
Eurogamer:
Dance Central 8
Kinectimals 7
Kinect Sports 7
Kinect Adventures 6
Joy Ride 5
CVG:
Kinect 8.8
Kinect Sports 7.9
Kinect Adventures 6.3
Joy Ride 5.3
Videogamer.com:
Dance Central 8
Joy Ride 6
Destructoid:
Kinect
Dance Central 8
Your Shape Fitness Evolved 8
Kinect Sports 6.5
Kinect Adventures 6
Pretty solid imo with Joy Ride unsuprisingly the runt of the litter.