After reading post after post after post on hacker news about NoSQL solutions being either the second coming or the devil incarnate, I figure I mind as well chime in. Quick and easy, here's how it goes: Right tool for the job. If you have extremely dispersed data that doesn't always follow a tight schema and the hardware to support a NoSQL solution, then use it. If you have data that follows a rigid structure, isn't all that complex, or needs a serious administration language, go with SQL/RDBMS. Comparing NoSQL vs RDBMS in the sense that one is a replacement of the other is a bad path to head down. Both can co-exist.
Choosing which solution to go with should be driven by a few factors. The primary one is application needs. Does your application and data fit better into one or the other, with considerations for speed and connectivity. After that, you need to apply some business needs. What is the cost of one versus the other? Cost can be broken down into numerous things, such as licensing, hardware, bandwidth, and administration costs.

NoSQL and RDBMS are not enemies. They are friends, who want to help you when you are in need. Look at what your application and business needs, then choose. Stop with all the "SQL is now obsolete" or "NoSQL is crap". We need them both.