The New York Times is reporting that two main areas of focus for tomorrow's WWDC keynote will be Healthbook and the "smart home".

The health app will initially pull data from third-party fitness and health-monitoring hardware, the person said, but it will most likely be able to connect with a smart watch that Apple is widely expected to release this year.
Apple is also expected to make an announcement about its efforts with connecting to so-called smart home devices, or home appliances that can be wirelessly controlled with a smartphone, like light bulbs, thermostats or door locks.

No big surprises here.

The smart home appliance that I'm most looking forward to is a smart lock. So far there's not much going on there, but I think it would be the most useful of the areas mentioned about. I have a Nest thermostat, and it's great. I actually wouldn't mind Nest getting into locks.