With rumours of a wider beta launching imminently, I thought it was time to call the MSN's UK advertising people. It was with some surprise that the guy heard me saying a beta was imminent - he said "hmm... you're the second person asking that...".
So, I left him to do some catching up, as he sells adverts. He came back saying that the official line is that the UK product is not due to launch until Q2 next year.
I doubt they will hold off that long, unless current legal obligations with Overture are in placde, but I can only pass on what I was told.