You're going to shard a SQLite database into a series of objects to deal with "large" containers?
There are tricky problems to solve, of course. How do listings work? Will shards ever be collected? What are the performance tradeoffs? How does replication handle shard conflicts?
These issue will be worked out, and it should eliminate the write bottleneck in large containers. (Note that reads are/were never affected by this issue.)
This implementation of container sharding is something that is being evaluated. It may or may not ever make it into swift itself.
Why don't you guys use a proper distributed database to handle container mappings/etc?