Well, she has gone to her family home this weekend.
About the "breakup", "cooling off", the "time and Space".... I see some various possibilities:
1) It's another "cooling off" (time and space, or something like that) as the softer version from Hello! says.
2) It's genuine, and permanent, maybe because Middleton has second thoughts (maybe the media, or maybe she is more ready for commitment than him) or because William is in love with another (maybe Jecca, I always suspected it's possible)
3) It's temporary to get the media to back off the Kate stories and get some attn back on the big anniversaries this year: Charles and Camilla, Diana concert, the Queen's Golden Wedding anniv., maybe even get some glory back on Haz and Iraq, who knows. It's too big for Windsor markers to be upstaged by Jigsaw accessories buyers. Maybe she and the prince came to a private agreement to spend as much time apart so that things will quiet down about she can have the privacy she seems to want.
I tend to believe the third possibility but I don't expect anyone to agree. In fact, I imagine my belief is an unpopuar one.