There's a great quote I read, at the end of this article. It says: "...if you think that switching to NoSQL will just let you hand-wave away all of the challenges of running a database, you are terribly misguided." The context is that all too often people looking to move away from some of the hassles of working with RDBMS platforms, which includes working with the DBA, haven't completely thought through the issues.
I do think NoSQL has a place in the world. There are domains of problems that I'm sure Riak, MongoDB, and others, solve in a more efficient way than SQL Server, Oracle, MySQL, and other relational systems. I'm not sure what they are, and to some extent, I haven't seen good guidance on where particular platforms excel. Most of the articles and pieces on choosing NoSQL seem to be trying to sell me "why a particular platform can replace my other one", and telling me to add in things like transactions, but not explaining the drawbacks.
However in all platforms, we often forget that there are really two frames of reference that matter. We need quick ways to work with data, insert it, update it, query it, etc. This is the development frame of reference, and it often dominates discussions of platforms. For good reasons, as developers are expensive, but that's only part of the system. We also need to consider the operational portion of managing data and applications. When I have those needs to rebuild indexes in relational platforms, or the requirement to periodically merge/remove old versions of documents, or even manage clustered, horizontally scaled resources, we need operational maturity.
In some sense the DevOps movement is built around merging these two frames of reference into the minds of all those involved. I hope that movement continues to grow and mature, and we learn that developers and operational staff are both necessary, and both need to function in a symbiotic, harmonious fashion.