I'm glad the upgrade is only a hundred bucks.
I haven't delved too deeply yet, but the coolest thing I've found in my three minutes of use is that in the two track editor, you can boost the gain of a selection just by selecting what you want, then adjusting a knob that appears at the top of the screen. Makes Normalization pointless, and this is a lot quicker!
Here's a screen shot of what I'm talking about.
And another cool feature that I'm dying to try is that Audition 3 supports virtual instruments. 1.5, which I use on the show, does not. So you can imagine my dismay at the fact that even if I wanted to, I couldn't use something like EZ Drummer! Well, version 3 supports those things, and I'm going to try a free virtual drumming package that was talked about recently on PSN. I'll keep you posted.