I'm thinking about buying my first iMac. I'm currently using a 5 year old Dell XPS laptop and need to upgrade. I went to the Apple store this weekend, and the new 27" iMacs look great. However, I've heard that Apple may change the case design of the iMac case shortly. Is there any truth to this? I'd hate to buy a new iMac simply to have them improve the case a week later.