Scoble has an interesting post up on ad relevance and paid results - and it looks like Google is going with a "less is more" approach on the ad front. The part that grabbed my eye is how much more relevant the paid results were on Google (and I've noticed this in my searches as well - when I don't know a company's website URL, the Google search usually gives it to me as the first result in both the main and paid results).

All of which tells me that Microsoft and Yahoo still have a lot of catching up to do in this space.