Its something that is quite unique and and new not a new K/V-Store, it will take time to really understand this. I watched the Video and things become clearer but I wouldn't know how to discribe it in a paragraph.

The "special sauce" is that much of the work is done localy (in memory), you can use very powerful datamanipulation, and its ACID. That my understanding so far.

It's a remote distributed MVCC data store with a total ordering of writes maintained by a transaction service, nonblocking reads bypassing the writer, and a local data analysis system that reads and caches the relevant facts from the remote data service. Roughly.

It's a database, quite different from any that are currently out there (you should read the white paper). Although one of the initial pricing models is to sell it as a cloud based service, that's incidental to the technology and why it's cool.

There's a video on the home page that gives a decent overview and speaks to that "special sauce" that makes it different than relational / nosql dbs. That's probably a good place to start if you aren't in the whitepaper reading mood.