This worries me. If someone searches for "ipod", why shouldn't the zune be allowed to advertise on the results page?
It should be completely up to Google how they want to monetize that results page, and which adverts they want to display there. Not up to a judge working from antiquated trademark law.
What's more, it's useful for the user. It's nice to see related things that might be of interest.
Here's the analogy:
* Man goes into shop
* Man asks sales assistant "Where are the iPods?"
* Sales assistant responds "Aisle 9"
* Man walks to aisle 9, and sees not only iPods, but various other mp3 players.