You're all familiar with the features announced for Leopard at last year's WWDC: Time Machine, Spaces, and new iChat/Mail apps. But there's definitely going to be more.
Wired has a piece on core animation, the developer animation suite that will make regular apps sparkle.
Also, Computerworld is predicting an alliance between Apple and Google to incorporate some of Google's web apps into .Mac. That should make loyal users of the stagnant .Mac platform happy. Or at least content enough to keep shelling out for that @mac.com address.
Here's our wishlist.• Tight integration with iPhone. There's going to be iTunes and iPhoto integration for sure, but let's get some stuff like proximity detection, auto-file system syncing, auto-syncing of Mail, Safari, and even remote control of your Mac from your phone over Wi-Fi. Heck, why not make it a super fancy remote when you're watching AppleTV or FrontRow.
• A better Finder. Better known as FTFF. For something that integral to everyday usage, that thing sucks.
• Native Windows apps like Parallels. How about Apple just buys Parallels and integrates their development right into the OS? That'd be something.
Those are the big three. How about you? What would you like to see in Leopard?