"Touchscreen, Weather-Proof, And Of Course Socially Connected".
Here's a more complete review (from the link above).
The cool feature for me is that you can actually download other peoples' runs and compete against their time. When I was using my Forerunner 305 I used that model's feature where you compete against your prior time regularly. Unfortunately, the 305 wasn't very water resistant.
I now have a Forerunner 310XT, which I use occasionally. It actually saved my butt when I got lost on Pikes Peak this summer, but I mostly use it when I'm running on trails, so I can tell what the distance was.
Trail sign distances are very unreliable, I've discovered.
I'll be interested to see if a sweaty touch screen works, but hopefully they've tested that. ;)