I haven't read the GraphLab paper in detail, but note that Google itself developed a new framework called Pregel for doing graph-based data processing that does

I haven't read the GraphLab paper in detail, but note that Google itself developed a new framework called Pregel for doing graph-based data processing that doesn't fit MapReduce well. They have a paper on it at SIGMOD 2010. So there is definitely a need for things other than Hadoop/MR.