MI character cameo in RED GLOVE?

I tweeted to Cassandra Clare and Holly Black that I really enjoyed Jace's cameo in White Cat. Cassie Clare responded in saying that there is an even funnier reference in Red Glove which is the sequel to White Cat!! Not sure if the reference is still Jace versus another MI character but my guess is it is since Cassel mentioned that Jace was someone who was from his dorm. Can't wait to Read it!! Also I wanted to know if cover art was finished for the sequel and Holly Black confirmed that the cover art for Red Glove is almost complete!! =)