If you haven't played with WP7 before, it's a lovely change from iOS, Blackberry, etc. It's Mango, and if you don't follow WP7 much it's got over 500 new features from the original phones that came out last year, and a huge amount of big fixes. They are already sorting out updates for the battery and the camera, both which need it to be honest. Other than that, having a built-in satnav (that's also getting an update, off-line navigation!) and tonnes of apps available it's awesome.
Ill keep you posted on updates to the device and how much it changes.
Should've pre-ordered, you would've got a free xbox 360 slim from Orange.