A WebmasterWorld thread reports UK Yahoo! Search Marketing advertisers receiving notification that the minimum bids accepted will be lowered to 5P (£0.05). Not all keywords will receive the lower bid of 5P, some will remain at 10P (£0.10). Which ones exactly, I am not sure.
I believe this also applies to Germany, Austria, Switzerland.
The new bid prices go into affect January 19, 2007.
Forum discussion at WebmasterWorld.