I think it would be a mistake to think of NoSQL as a replacement of RDBMS. Its main goal is rather to make our lives easier for a set of scenarios that were created with the read-write web. I'd encourage you to take a look at these NoSQL usecases: <a href="http://nosql.mypopescu.com/tagged/usecase" rel="nofollow">http://nosql.mypopescu.com/tagged/usecase</a>. Hopefully that would give you an idea where some of these systems are fitting in. If you check other presentations on MyNoSQL you'll notice that many live systems are using a mixture of RDBMS and NoSQL.<p>:- alex