Wow. I was just about to post about this.
My friend works at Apple as a customer service rep for their online store. Here's what he just posted in his blog
here's the thing... something big is about to happen at apple, and they won't tell us what it is, but this big thing is happening on wednesday, my day off, and everyone in the entire call center is being put on mandatory overtime from wednesday to friday, which is when i want to leave. it's probably a new product release, probably the new operating system tiger, anyway, i've been told by the lady in charge of allowing for time off that i not only cannot have the friday off, but my normal day off of wednesday is being switched to tuesday for this week.
He thinks it's Tiger, but my assumption was new hardware, something along the lines of an iPod mini revision. From everything I've read, Tiger isn't near ready but the iPod mini has supposedly been shipping with 5GB drives for a while now.