It certainly seems that the NoSQL movement is largely fueled by two facts:
1. MySQL sucks
2. Oracle is expensive
I'd love to see Postgresql get more attention, as I feel that they have scaling up and scaling out handled fairly well, whereas MySQL/InnoDB has a hard time even scaling up (which is why the Drizzle project even exists).
Does Postgres partition across a cluster? That's what we're talking about here.