Apple's new operating system, Leopard, was released about 5 minutes ago. If you edit video -- and I assume you do if you're reading this -- read the post at Little Frog before you rush to upgrade. (Little Frog... Leopard... What is it with the animals today?). Shane Ross has some tips for upgrading, which I wholeheartedly endorse. The golden rule? If it ain't broke, don't fix it. Read on...
UPDATE: Less than 24 hours after going on sale, Leopard is... going on a rampage. While there are, doubtless, some happy early adopters out there, several folks are making some noise about all of the problems they're having post-install. Topics in the Apple Support Forums with such inspiring titles as "Installation appears stuck on a plain blue screen" are not reassuring.
So, for now, beware. As one MacFixit article states:
Apple, having allowed this shipment to slip six months already, has had to get Leopard out the door before the end of October by hook or by crook. You may reasonably conclude that this cake is probably not entirely baked. As with Tiger, an early software update (10.5.1) will likely be needed to correct a multitude of issues. Until then, consider yourself a beta tester.
If you absolutely must install Leopard, read this MacFixIt article about the best way to install Leopard.