In case you don't know, Drizzle is a cloud-directed, Linux-leaning, stripped-down, hitherto for unsupported, GPL 2 MySQL 6.0 fork that Rackspace is betting will infinitely scale, or at least scale better than MySQL.

It looks like Rackspace means to go to production with the thing this year. Hopefully it will be stable.

Drizzle runs the risk of not being as stable as MySQL, because the Drizzle team is taking things out and putting other stuff in. Of course it may be successful in trying to create a product that's more stable than MySQL. But creating a stable DBMS engine is something that has always taken years and years.

Half of Rackspace's customers are on MySQL so there'll be some donkey-style nosing to get them to migrate.
Rackspace evidently wants its new boys, who were not the core pillars of the MySQL engineering team, to hitch MySQL, er, Drizzle to Cassandra, Facebook's imitation of Google's proprietary non-relational BigTable database system ironically named after the daughter of the king of Troy who was endowed with the gift of prophecy but fated by a spurned Apollo never to be believed. (Something, one would think - silly geeks - no database should ever be called especially - if arguing myth - it was going up against the sublimely authoritative Oracle.)

Anyway, Cassandra is "a distributed database with a BigTable data model running on a Dynamo-like infrastructure. It is column-oriented and allows for the storage of relatively structured data. It has a fully decentralized model; every node is identical and there is no single point of failure. It's also extremely fault-tolerant; data is replicated to multiple nodes and across data centers. Cassandra is also very elastic; read and write throughput increase linearly as new machines are added." Source