I don't think so. Does Cassandra provide guarantees regarding the ordering of queries? Cause I couldn't see that.

Another problem I can see is when you write to 3 nodes, have W=2 and a write succeeds only one one node. Then later on through read repair the value propagates to the other 2 nodes. So our write "failed" but really in the end succeeded. I'm not too much into the Cassandra details but those two things immediately came to my mind when reading some of the wiki pages.

It boils down to not using/offering algorithms like 2-Phase Commit or Paxos but more sloppy quorums.

So from what I can tell, Cassandra can not guarantee strong consistency. But then again I could be wrong and missed something.