There are no songs post 2007, so I will assume 2007 is the cutoff. Even if it wasn't, who cares? About.com is not some hugely respected source and they are just sharing their opinions of what they think are the greatest pop songs of all-time. They can't satisfy everyone and not everyone is a fan of some of the exclusions you guys are mentioning.
For some reason, "Yeah!" isn't very acclaimed and hasn't aged well to many people. It's not forgotten, but it's just not highly-lauded. Maybe it has something to do with it having strong elements of the Crunk fad.
sucks to be honest, but i know climax better make every year end list this year