Nah, 2nd generation 10GB for me.
Advantages of 2nd generation=longer battery life, can use ANY 6 pin firewire cable anywhere. The new 3rd generation ones have a what, $40 cable that connects to your computer's firewire port? I have a firewire cable at work, at home, and the original one with 4 pin adapter for my laptop. You get one cable with the thing and have to buy any additional ones.
With that said, the 3rd generation does look pretty nice and it is lighter. I'm not sure how I feel about the buttons not being around the touchpad anymore but I'm sure it's very easy to get used to.
Gaidin