Posted a design for balanced preferred content. This would let preferred content expressions assign each file to N repositories out of a group, selected using Math. Adding a repository could optionally be configured to automatically rebalance the files (not very bandwidth efficiently though). I think some have asked for a feature like this before, so read the design and see if it would be useful for you.
Spent a while debugging a problem with a S3 remote, which seems to have been a misconfiguration in the end. But several improvements came out of it to make it easier to debug S3 in the future etc.