These are in no particular order. I add them as I think of them.
- Local ingestion durability.
- Use the Cassandra Fat Client for ingestion, rollup and/or query
- l2met integration (http://r.32k.io/l2met-introduction)
- Fluentd integration (http://fluentd.org)
- A distributed test suite
- Internode coordination (obviate manual shard assignment)