I suspect the pricing isn't that good, and they would rather people bought from the UK rather than importing. I bet when the pricing is announced Apple are worried that the number of people attempting to import them will increase.
I cant see that is would make any sense to have the cost of the ipad in the UK more than the cost of importing one. Having been delayed twice by Apple i am sure I can wait a week or two for an import.
I am willing to pay a maximum of £600 for a 64Gb wifi only ipad. Otherwise I will import.