It has massive potential. For one, they didn't waste space inside the device on things that the iPhone already has. This leaves space for other things like haptic feedback. It also works seamlessly with the iPhone/iPad. So you're reading an email on your Apple Watch, but you unlock your phone and the email is there ready to be replied to.
Second, I think the fact that Apple figured out a wearable device should take advantage of the contact it has with skin is massive. This will have huge implications in the health sector. The fact that it monitors you and sets goals for you is a big plus in my book.
Third, an Apple Watch App Store! The sky is the limit here. The iPhone was mostly a cell phone before the App Store. The Apple Watch is already more than a watch, but it will only get better from here. Developers are creative.