Emre Sokullu, as a guest blogger on Read/Write Web, has a thorough look at Yahoo’s recent acquisitions, and concludes:

Yahoo’s latest acquisitions are cheap and smart. In effect the Peanut Butter manifesto
is actually the new de-portalization strategy. However, although it’s good not to kill
brands (but keep them as separate entities and don’t touch the soul that brought them
success) Yahoo could be faster in getting the advantages of having so many related
products. For instance, del.icio.us and Yahoo Search, or Jumpcut and Yahoo Video – these
really should have been brought together already.

I think Yahoo’s been very opportunistic, and I am not sure that I follow the overall strategy here.  I agree with Emre that there’s the de-portalization, but outside of that, I see no overarching pattern.  I can imagine that the corp dev folks at Yahoo are nervous to make bold moves, with Wall Street eager to pick Google as the winner of the internet wars.