Comparison of NoSQL systems

Here is an interesting spreadsheet comparing NoSQL systems:

Source:
University of Washington
Introduction to Data Science
https://class.coursera.org/datasci-001

Next trendy open source projects

If past is any indication of future trends, surely next trendy open source projects will be what's currently developed at technology leaders like google.  Similar to hadoop becoming popular after google published its map-reduce paper, and then big table implemented as hbase by open source community, surely there is a cool factor as well as value and following in building open source implementations of:

• tenzing
• dremel
• pregel
• megastore
• spanner

NoSQL databases and CAP theorem

CAP theorem claims that it's possible to achieve only two of the three in a distributed system:

• consistency
• availability
• partition tolerance (# of nodes)

How do NoSQL databases stand on this?  There is a nice illustration from Shashank Tiwari: