Just a heads up for people who may not have played with 0.7*.
CASSANDRA-1377 changes the set of allowed characters for keyspace and CF names, they now must match the \w reg ex class. So letters, digitals and the underscore.
If you've been naming your keyspace with a domain name (like I was) you will need to change it.
The information is in the CHANGES.txt on the current trunk. I'm sure the dev's will give a migration plan when 0.7 releases.
It's not a big deal, but if you have the chance to change your keyspace name now it may make your life a little easier later.