Hypothetically, since adverts were added from the 2.0 patch, so you should be able to delete HD, download it again, but not download the patch and you won't have them. You'll sacrifice playing online, though.
Someone upthread mentioned still getting the ads even signed out of PSN and with the cable unplugged. I wonder if setting the system date back before last Thursday would disable them...
Edit: Nope, it didn't.
Last edited by Zach Keene; 1st August 2009 at 07:32 PM.
Reason: Never mind