Sometimes the best way to help somebody open his eyes is to give him an unexpected gift.
Unless it's all an act and there's an actual design firm that's going to save the day at the very last second (not that all design firms are capable of such a feat) Yahoo seems to be in the process of shooting itself in the foot:
Although some people will see the following suggestion as even worse than so-called "spec work", if we concede that Yahoo is unlikely to abort this ridiculous headless-chicken-in-quicksand approach, then maybe we can help them see the light by arriving at a logo that the design field will end up supporting as a positive example.
So, here goes another trademark crazy idea:
Since it's too much to expect somebody making such an effort from scratch, start with any of the half-baked (or just plain inedible) logos above, make it good, and send it as a gift to Yahoo. FWIW the one, and only one, I personally think has great potential is the one for day four:
BTW anybody with connections at Yahoo is kindly asked to point them in this direction.