[Dovecot] Dovecot and scalable database storage

[list at airstreamcomm.net]

I saw some interesting mails from TImo back in 2009 talking about the idea
of using something like Cassandra db or similar as a storage platform for
both email and index/logs.  I was wondering if this has been discussed
since then, and if there are any plans to support something like this in
the future?  I have been playing with Cassandra and found that their
RackAwareStrategy gives you the ability to replicate writes to as many
nodes as you would like, but more importantly what nodes and one of those
nodes could be defined by what rack it lives in or what data center it
lives in.  This means multiple sites high available storage clusters,
seemingly a system that dovecot could benefit from in terms of performance
and redundancy and simplicity.  Any takers?