VoltDB

VoltDB looks really cool. It's an open source database that I think is based on the highly interesting H-Store research.

For "Version Next", the roadmap includes:

• High Availability: replace failed node on the fly

Which is, I think, a great sign of how far from the commoditization of scalable data storage we still are. In almost every project, HA is planned for the next version. Only Cassandra seems to scale automatically at the moment.