I also discussed this with some guys that I used to play with who currently play 2000NL (hookz, and hazards21) they agree that unless a really unusual sitation presents itself you push this baby.

hookz and hazards say he goes broke with KK every time , you can check out his hand history http://www.pokerhand.org/index.php?page=list&user=Hookz
This dude moved from 25NL to 2000NL in 6 months.