AdWords Agency Discount?

I've been looking around for a couple days for confirmation - one way or the other - of the existence of a discount program for agencies that use AdWords.

I found a thread in the Search Engine Watch forums that leads me to believe such a program does exist, but at the same time makes me wonder what the criteria is for being accepted into an AdWords discount program? Is it your monthly spend? Do you have to be a GAP (Google Advertising Professional)?

There has also been some discussion in the Digital Point forums. Here's a link to the thread.

If you have any insight or information regarding the existence and qualifications for an AdWords agency discount program please share!