Very informative article for NoSQL noobs like myself. If I understood him correctly: Scalability (an implementation) is the partitioning and distribution of data for databases across multiple machines working interdependently. Data and query model (an interface) is the essence of NoSQL since it is the equivalent of what I'm used to doing in SQL, which is hitting the database with a query; yet, the obvious advantage of NoSQL is that we no longer have to hit it (the db) with SQL and can instead take advantage of an API that queries our database specifically designed for however we are storing it (into our data-model). The API is as much as an interface as SQL is in a relational-database design. Lastly, persistence (from what I can tell, an engine optimized for a data-model) is what I think NoSQL is really all about because each engine is storing and fetching data according to specific a data-model which is optimized for run-time.
Please correct if I'm misunderstanding anything or everything. Also would someone care to elaborate more (educate me) on scalability? Is this same sort of scalability Amazon's EC2 servers are optimized for?