It appears that I can only create a stack in the dock, not a folder (If anyone knows otherwise, let me know). This seems odd at first, but a stack is really just a folder that displays its contents in an atypical way. Still, people will complain, just as they did when column view was added to the Finder. Speaking of the Finder....
I'm eager to watch my G4 iMac freeze solid when I try coverflow view. Talk about spinning beach ball. The movie and multi-page previews are very cool, but I suspect they'll require some horsepower to pull off nicely. Apple states that a Mac with an Intel, PowerPC G5, or PowerPC G4 (867MHz or faster) processor is required for Leopard. At 1.25GHz, I'm scraping the bottom of the barrel.
The desktop itself is bare bones. In fact, no hard disks are displayed at all. The show up in the new sidebar, but I'm curious to know if you can activate them with the Finder preferences. When John found the beautifully laid out PDF he needed on his networked Mac and dragged it to his own, I assume it went to the "Downloads" stack, and that he could he have dragged it to the desktop.
A bit more synergy between devices. Many have noted that the iMac resembles the iPhone (and that the G5 model looked like the iPod). I noticed that the slider to enable Time Machine in the Finder looks much like a slider on the iPhone's UI.
Ah, Time Machine. People either love or despise that UI. I will admit that it seems heavy on the eye candy, but for someone like my mother (and the majority of computer users are like her), it's an easy-to-understand analogy. Geeks like you and me (if you don't mind the label) forget that most users don't read the websites, subscribe to the magazines and take part in the discussions that we enjoy so much. Time Machine's look may seem silly, but I believe it will make something that many consider tricky - backup and restore - understandable.
Oh, Apple. I detest bandwidth-hogging HTML email messages. Now you've given everyone and their brother the ability to create these time-wasting monstrosities...and send them to me. I'm not happy about this. The web is for "...creating stunning templates to impress your friends, for any occasion." Email is for simply pointing to those projects. You don't cram your museum's feature content onto the brochure.
On the other hand, data detectors looks wicked cool. I'm eager to try that out.
The notes feature could be useful, but the orange-on-yellow highlight scheme has got to go. Perhaps the idea was that my To Do's would be so painful to look at, I'll be more motivated to complete and delete them.
Consider this the observations of someone who hasn't used Leopard yet. What are you looking forward to / dreading?