There shouldnt be much of an issue, Apple usually release things with a worldwide adaptor for power (so you may just need to change the plug to a 3-pin) but most of us will just charge from our desktop or iPhone charger anyway!
As seems to be the case, I have written a full length blog about it
http://www.freeipadblog.co.uk/blog/2010/03/08/how-to-buy-an-ipad-in-the-uk-from-the-usa/
I think the most exciting thing is that if you can find 5+ people who want to ship one over too, you could fly to the states, buy them in a shop and bring 'em back - and save money!
g