According to John Chow, indeed they do. It's called the Google Display Advertising Network, and it's by invitation only. Google is targeting the service at large corporations, who are often interested in advertising for branding purposes than getting an ROI from selling a product.

"Google has been hand-selecting sites (no word on how many sites has been chosen) that they want to put in front of Fortune 1000 companies", says Chow. "The goal being to sell these big companies display and video ads at a very high CPM – unlike the AdSense network, the display network is 100% CPM based."

Read Chow's full commentary at his blog.