Spark cleans up some abstractions found in the Hadoop ecosystem but I would hesitate to call it the "next big thing" because it doesn't really address any of the core weaknesses of Hadoop. In Big Data, there are three touchstone applications that the current generation of platforms largely do poorly: real-time, geospatial, graph. Spark does not really address any of these. It might be more accurate to say that Spark…
Here are the papers for GraphLab and GraphX...
GraphLab: http://graphlab.org/home/publications/
GraphX: A Resilient Distributed Graph System on Spark (https://amplab.cs.berkeley.edu/publication/graphx-grades/)
See also "Introduction to GraphX - Presented by Joseph Gonzalez, Reynold Xin - UC Berkeley AmpLab 2013" (http://www.youtube.com/watch?v=mKEn9C5bRck)