I'm more concerned the carriers will see it as an opportunity for another monthly contract!
I'd love to have GPS on the Watch, just not convinced about the battery life trade off.
I actually would embrace carrier bundling of Apple product services. The more devices that can use carrier services, the more likely that will happen. I'd love to pay one package that allowed me to use my minutes across whatever device I activated. That would simplify so many things ...
As far as GPS is concerned, I'd rather have it than not. Current GPS watches with lower capacity batteries than the Watch get 8-10 hours of constant use. The Watch wound't necessarily need anywhere close to that kind of continuous use, and the user would determine when to turn it on and when not -- just like taking and making calls on the Watch currently, which if the user used their watch exclusively for that would drain the battery dry in 3 hours. You only get 6 hours streaming music continuously as well. So there are already trade-offs the customer has to be aware of, and GPS can certainly fit into that category -- especially where the phone is typically always present to provide those services instead. We're really only talking about when people leave the phone behind, and really, how often is that the norm?