Wow, his style has gotten a lot better in the past year or so. In a recording I have of him from May 2008, he was a lot more serious and was never like Dave.
I agree. The majority of this change took place over the last 2-3 months after working a few 2-person shifts with Samantha Mohr and then with Alex Wallace; he was pretty funny during the 2-person shows. Especially after his shift with Alex Wallace, he started being funny during his solo shows. He's only been off the wall like Dave for the past month or so.
I don't know what suddenly set off the spark in him, but I hope he stays funny like this.