That was a code backup, something we don't do very often as we don't need to. (code is tested and then uploaded, so we already have the "backup" of the live LoS before it goes to the server). However, we'd done a few "hot-fixes" with the creatures, rooms and code over the past few months, so we had to take the backup this way. As I said, it's rare that we need to do that.
Player backups are taken daily, so don't worry about continuing to play. The player-files will be backed up and transfered across at the moment that we switch the servers, so you'll be able to play up until pretty much the last moments.
Player-rooms are backed up with the players, before you ask.
So, just to make it clear, you won't "lose" anything if you continue playing till the last minute, as a standard player backup will be done as we move.
--Kaedan