CPAN Instant Update Mirroring
If you've got a CPAN mirror and you haven't had a chance to test out the instant update mirroring, I'm here to suggest you try it out. I had a few spare moments earlier this week to test it out and I'm happy to say that the setup is trivial. If you follow these instructions, you can get yourself set up in a matter of minutes. In my case it was installing a couple of modules and then firing up the sync from the command line. When I checked back later, I had around 9 GB of CPAN goodness. As it happened, I uploaded a dist via PAUSE later in the day. I remembered to check my new instant update mirror a few minutes later and yes, my upload was already available in the mirror.
This is good for a couple of reasons. First, no more waiting for hours (or even a day) for files to appear on your local mirror. Second, this means that if you're running your own CPAN indexer, you don't have to do anything really fancy to get new dists as they are released. You can still do fancy things, but if you can put up with a 20 second lag, you're all set.
As far as MetaCPAN goes, we have the option of using Moritiz's code to monitor FriendFeed for dist uploads (noted above) or just watching the filesystem for changes and then indexing the new dists as they get added.
I think this is a really substantial improvement to the CPAN infrastructure and a big thank you goes out to the folks who did the heavy lifting on this!