Hi,
At the moment it would seem that an UnCon for 2007 is highly unlikely. As it's becoming increasingly expensive to do it in a London venue - and the lack of a truly suitable one is an ongoing problem - Dennis Publishing, who do the practical organising of the event, are looking at other possibilties for UnCon's future.
Whether this means a non-London event, a series of mini-cons or something entirely different I can't say at this stage. But 2007 will most likely be a hiatus while these things are looked at in detail.
It's a shame, obviously, but we do hope that it won't ruin your year!
If and when anything further emerges, you'll be the first to know.
Best
David Sutton