Just wanted to share my experience of the new Apple Magic Mouse with those, who like me, have been considering forking out a huge £56 for one. I bought mine off ebay for £45 after trying it in the Apple Store Brum and I can confirm it is the best mouse I have ever used.
I've used every Apple mouse over the last twenty years - wedges, pucks and mighty mouse but have always stuck with my Pro Mouse - however the feel of the Magic and the tablet like scroll surface of the top is superb - being able to swipe my finger over the top to scroll up/down left/right in any window including palettes is fantastic, and the zoom feature whilst holding the control key is an excellent addition. And the wireless Bluetooth works seamlessly - I have a stash of AAA rechargeables for future use which is well worth considering for the long term, though I have no idea the installed batteries last.
One of the big pluses is it is a pure Apple mouse, the problem I had with the MIghty Mouse is that if you hopped onto someone else machine all sorts stuff would happen Expose etc when you touched a particular area but with this it is simply whatever hand movement you perform anywhere on it.
It's worth checking out ebay for the best price but for those who want to buy from a store Apple is looking like the best bet, particularly if you have QuidCo, TopCashBack etc. If you find a good deal please add it below...