I am interested in the features of the Apple Sport watch for its fitness training features. I think this will be a large portion of their market. Runners are used to paying $300+ for a GPS-enabled watch.
Here is a summary of the Apple Watch features from a running perspective. I really like the strapless heart rate monitoring feature, but I will wait until early adopters report back on how effective it is. It will also have to be proven to be waterproof before I took it out on a kayak.