In reply to Gibson:
My fear would be that for a repair you'd need to return it to where it was purchased, and that Apple UK wouldn't go near it. The warranty is still honoured, but the warranty is with the vendor (who is effectively a local agent and not the parent company). I have had this happen to me on several occasions, but would confess I don't know how Apple handle this.
But Ipads are pretty reliable, so I would be ok buying one from the US, knowing full well that if a problem arose it would need to go back there.