I decided to implement it in my cassandra too, but i am using
zookeeper for cluster management.
I scraped idea of consistent hashing with random tokens. There is too
much variance with effective ranges allocated to nodes in large cluster,
you need to have lot of ranges which is quite large overhead because of
suboptimal implementation in current Cassandra.
I decided to go for mtrees on top of clock allocator. Because mtrees can
overlap they can take care of replication as well.
there is couple of bugs in Cassandra 1.2 after you enable vnodes, but
you will never warn user about vnodes not production quality, don't you?
Look at Redhat, some features are marked "Tech preview". Your thinking
is: ppl should test it before putting it into production. You can't
expect user to test all possible code paths.