Just read an excellent article five-predictions-for-your-database-in-2011 predicting various trends in Databases in 2011. They predict a decline in NoSQL databases and move towards Database as a Service (DBaaS). DBaaS is about an entire change in philosophy producing efficiency, fluidity of resources, scale out, paying for actual usage and being able to be elastic. Elasticity discussed here
DaaS (Data as a Service) is about data collections in the sky.
DBaaS (Database as a Service) is about providing full database functionality.