I have to leave for work soon, and the patch download hasn't started. If I leave my launcher open and set my computer to never sleep, will it happen automagically while I'm away?
It should work just fine. However, I have had the odd patch error that stops it in the middle of downloading, which basically means you will still need to reload the launcher when you get back. But this is fairly rare. Most people do just leave their launcher up all day for it to do it's magic while they're at school/work.