What's unique - While there are many data aggregation services and some visualization, one has to go beyond correlation between different data sets to level up. Correlation is great but it is after the event. I think what we need to do is learn from users data and combine knowledge of others and the world around us to suggest somethings which a person might not even have considered. It's like Netflix movie recommendation. Depending on what you like and what others like you might like there are recommendations. Ofcourse I am overly simplifying but that's the basic concept.
Ah misfit yes, the only reason it ends up there is because the market share is mostly divided in the 3 trackers. Jawbone, FitBit and Misfit and even thought they don't have an API I am certain it will be there soon(sooner than I can release I hope ). Else they have no chance of being relevant in the market going forward.
MyFitnessPal has been some page scraping initially using mechanize, but they announced an API http://www.myfitnesspal.com/api
Even fitocracy does not have an API.
Btw I love ZenoBase, but with all due respect I think it is a little difficult to get started with. Have you tried addapp which just released?