I've never really wanted a product enough to line up and try to get it the minute it becomes available. Mac OS X Leopard was no exception. I had originally planned to get it in a couple of weeks once the dust settled and the early adopter kinks were fixed. But when I noticed that the campus bookstore was going to have a launch event with a special door crasher price of $99, I figured I'd go save the $16. I got to the store 10 minutes before the 18:00 launch time and got ticket number 39, I got in just in time as the last ticket was handed out to the guy who came in a couple of minutes after me. I helped myself to cake and APPLE cider (get it...), and waited awkwardly for ten minutes while people around me were either talking excitedly about the new OS, or making remarks about the absurdity of lining up for an OS launch. I was definitely in the latter camp, but I'm all about the savings. I had originally intended to stick to my wait a week approach to installation. A quick look through the forums made it pretty clear that Leopard wasn't going to break anything major the way Tiger did a couple of years ago so I decided to install the thing later that night.
As far as first impressions go I would characterize Leopard as an extremely subtle release. While Leopard comes with a slew of interface changes that seems to characterize Mac OS releases, I find the latest change to be the least jarring of the previous changes. It's probably because the interface is taken from iTunes and I've been usng the hell out of that program. Among the features that have immediately made themselves useful are Quick Look and the various feature additions to Mail. I'm sure Quick Look is going to be used as main form of casual browsing of various files, and as a person that has Mail constantly open the addition of RSS and notes and to-dos are already quite useful. Time Machine, the feature most people seem to talk about, is easy to setup and runs nicely in the background. I haven't had the need to go back in time yet so I don't have much else to say. The new iChat/Photo Booth effects are fun, but I haven't really used them yet. I can definitely see myself using the new Screen Sharing feature to help troubleshoot and demonstrate things for my parents. I'm not sure how much use I'll get out of Spaces, virtual desktops sounds good but I'm not sure if I'll be able to overcome my years of single desktop experience, similarly I rarely use Expose because I'm still stuck tiling windows. Nothing in Leopard is a must get, and I wouldn't really recommend paying money to get Leopard to my casual user friends. But if you were leaning towards getting it, there isn't really anything that should stop you as far as I can tell.