The new server (Arclight) has shipped! Whooo!!! I dropped it off at UPS a few minutes ago, and it's scheduled to arrive on Thursday. That means it'll probably go online the next day, and I'll make the transition sometime over the weekend, probably late at night (late in the U.S. anyway.) While I'm going to take every precaution possible with all the data, I'd still advise you all to keep your own backup of your stuff, on the super-remote chance something goes wrong. Backup both your files, and your email (if you use IMAP) and remember that the new server is going to be SCP/SFTP only, no more FTP. It'll also be IMAP or webmail only, no more pop3.
If all goes well, 99% of you will never notice the actual switchover. I'm hoping to keep it down to a couple hours of downtime, but that all depends on how fast the machines can transfer data back and forth. The old server has to dump the database of every user, and then all files have to be transfered, where email and the databases will be reintegrated into the new system. Only 30 people or so have email to migrate, which I have to do by hand, and that's going to take me the longest. The plain ol' files should be pretty quick and scriptable. Like I said though, I'll probably do this in the early morning hours, like 3AM (0900 UTC.)