From a look at the comments since the original post on PPC pricing changes on the Yahoo Search Blog, it looks like Yahoo has just handed MSN Search more business?
As announced earlier this week, Yahoo is implementing a new pricing scheme for buying keywords based on quality, in some ways, similar to the way Google does.
In some 'niche' markets and other cases, it could be a (big) plus for some keyword buyers as the 10 cents minimum is going away. For those in highly competitive spaces, it could mean higher prices.
The 'account interface' is being changed as well and the FAQ's have been posted by Yahoo here.