I just got the heads up from my account rep at Yahoo search marketing that by the beginning of Q3, Overture is essentially going to be mirroring Google's interface and business model. Listings will be ranked based on CTR/maxbid (like Google), geo targetting by country/state/zipcode will be offered (like Google), instant approvals with an editorial review later on (like Google) and even the interface will be very similiar.
I really wish they wouldn't make these changes personally and would rather they didn't change a thing, but I imagine this would appeal to a lot of advertisers out there
WG