I don't think this "break up" was ever the real deal. William wants his mothers birthday celebration/concert to be the highlight of this summer. To do that, Kate had to go on the back burner in the public eye. I think the break up has been nothing but a public relations ploy. Once Diana's celebrations have passed, William and Kate will be back on, most likey with an engagement ring on her finger by next spring.
I don't think that would be possible. Kate was always expected to attend Diana's memorial concert. So why would they have this fake break-up in the first place? If anything, the break-up was bigger news than the concert!
If it was a public relations ploy, then it was a ridiculous one. The media dragged her and her mother through the dirt once a wedding wasn't in the cards. Kate was labeled a gold-digger waiting for the ring and her mother a Mrs. Bennett wannabe with no supposed social skills whose profession as an air stewardess was being ridiculed by WILLIAM'S circle. Why go through all that? It's dumb. Plain dumb. If they can't handle the pressure of the press, then they shouldn't be together in the first place.