In the preview videos released for Android Wear, you'll see quite a lot that you've seen before from products like Google Now and Google Glass, just translated to a smartwatch. The focus of Android Wear is in relevant contextual data, much of which you already get from Google Now like location-based weather, traffic data, reminders, travel info (airplane boarding passes, etc), and app notifications. There are the usual fitness tracking options that are already relatively standard on wearables, and interesting notifications like jellyfish warnings when you're at the beach. The interface is gesture-based, but quite a lot of the functionality seems to come from the voice command system, which does include the song recognition feature in Google Now.
Google has also started the rollout of the Android Wear SDK Developer Preview. Again, Google has been very careful to say that the SDK will allow developers to "extend" app functionality to wearables, meaning this is not a platform which will have standalone apps on it to start. Google has also announced partnerships with a number of manufacturers to bring wearable products to market, including LG, Samsung, Motorola, HTC, and Asus.
The info page also shows support from Intel, MediaTek, Broadcomm, and Qualcomm, which indicates that there should be quite a few different devices at different price points on the way. Even more interestingly, Fossil is listed as a partner, which could mean there will be some more stylish watches on the way as well.