2011/10/4 Paul Loy <keteracel@gmail.com>
Did you read the article you posted?
"We believe that this isn't the time to make large scale migration to a new technology. We will focus our Cassandra work on new projects that we wouldn't be able to ship without a large-scale data store.

There was big boom in network about, that Tweeter will migrate they tweets to cassandra, but than they reject this plans. This explanation sounds very vague. Why they have changed the mind? I find only one article about this: