We have confirmation from our Google reps that we can now exclude all parked domain sites, including those on the Google search network.
You can do this via the newly released Site and Category Exclusion Tool. Click on the Page Types tab, and you’ll see parked domain performance.
The tool shows data by campaign. You may find that some campaigns perform well on parked domain sites (unlikely). Make sure you have separate AdWords campaigns for Search and Content, so when you look at data from a specific campaign you will be able to tell whether the parked domain traffic was from the Content network or the Search network.
Kudos to Google for allowing such transparency in its partner network! Yahoo & MSN: Anyone home?