If you're in the UK and you've still not got a pre-order then I may be able to offer a glimmer of hope.
I was planning on getting one from Amazon.co.uk today but extenuating circumstances prevented me from being there when the pre-orders went live >_<
I was planning on just going into town on the launch day with some friends and getting one but I decided to have one last look around.
I found Argos.co.uk ( Shop for WII Console with Wii Sports Game - available 8th Dec. at Argos.co.uk ) and noticed the message underneath
I thought to myself that this would probably be left over but I decided to check it out. I gave them a phone and spoke to a friendly customer services rep who happened to live just 5 minutes up the road (its a small world) who was able to confirm to me that they could guarantee that I would recieve a Wii upon launch day (give or take a day or two because they post them in advance to try get them to the customers on launch day). Needless to say I placed an order of '1xWii Console with Wii Sports Game'This item will be delivered when it is released on 8th December.
Now I'm happy as can be. I just thought I would post this to try help people who may still have been looking for pre-orders in the UK.
Good luck to everyone in getting their Wii's