From what I've seen, Yahoo is allowing more ads to be shown on MFA sites which keeps the traffic steady but tanks the conversion rate. On the other hand, MSN traffic is looking strong and converting well. Yahoo is going to have some MAJOR problems in the next few quarters if advertisers figure out their game and flee like I think they will.
YOverture needs a complete overhaul and this may be what pushes them to do something different. MSN is coming on strong, and I much prefer a 3 horse race.
Without MSN entering the game, Yahoo would be content being second place. I can't see them happy in 3rd. Losing out to Google has become a fact of life for them, but to lost to MSN would be unacceptable. I'm sure Yahoo will wake up and start to innovate again.