I never noticed it in 2010, but during late 2006, and all of 2007, he added a really cool synth part to WTTJ. You can notice it in the LA 06 (20th) bootleg, and also the 07 Monterrey Mexico show.
I think he just tried his best to compliment the old songs, while he has a more in depth role on CD songs.
Chris rules though, I love him and feel his additions make everything "Better".