I phoned up my local dealer in the UK and it's similar to that in the US. £500 deposit to get added to the preorder list and then, once they are about to start manufacturing (I was told sometime in Feb '09) they'll give me a call so that I can go in, decide on my options (spec, colour, etc.) and put down another £500.
I put down the £500 and should be getting my car on the day of release. Sweet!
JJ.