I'd like to meddle with the way Debian distributed software. It is very silly that apt-get update downloads several megabytes of data, just to get the incremental changes since the last apt-get update. I believe it should be easy to implement an incremental update that sends only the changes since time t. This would require that each upload have a serial number, but either that already exists somewhere in the apt system, or it could be hacked in without too much trouble.
By my caculations a daily apt-get update could be reduced from several megabytes to tens of kilobytes.