Thanks, hoxty - it's from Game & I've had the confirmation email from them so it should be OK [fingers crossed]
(It was a bundle with Family Ski for £100, most places don't seem to have stock of Fit alone but the ski game sounds good anyway. Tesco would be the best place to get it if they ever had any in - I'm on their email alert list too but they've had none in 3 weeks )
I didn't know they were still so hard to get. I got one for dh's birthday (May) on a whim really - I knew they were like goldust, saw a scrawled sign in WHSmith's window saying "Wii Fit in Stock", thought "oh they've just forgotten to take the sign out of the window" walked in - they had loads - and bought one. Cue friends and family saying "you jammy sod, how on earth did you manage to get hold of one?!"
Good luck, hoxty, there have been quite a few emails I should've caught but missed out on just because I didn't see them until after they'd sold out again; if you can check your inbox more frequently than me it shouldn't take too long!