I'm a little behind getting this on the main site, but Cassandra posted another excerpt from CoG on her google groups. 

“Sebastian!” Isabelle called. “Don’t let her go upstairs!”

The boy looked up, startled --and a moment later was in front of
Clary, blocking her path to the stairs. Clary skidded to a halt —
she’d never seen anyone move that fast before, except Jace. The boy
wasn’t even out of breath; in fact, he was smiling at her.

“So this is the famous Clary." His smile lit up his face, and Clary
felt her breath catch.

Click HERE to head on over to the forums to read the rest of this exciting cookie. Thanks to SmashingCinderella on the forums for finding it.