Not a secret feature, or even anything that exciting, but I sure would like it if the Finder was improved to handle network shares better. A "Reconnect at Login" box a la windows drive mapping would be sweet.
Yes, finder improvements are a must. I want, like you, better network shares, and tighter integration of Spotlight into the finder (easier to use smart folders, multiple finder windows that self organize, whatever else those crafty Apple software engineers can think of).
integrate ical, mail and sickies - productivity hub for the mac. new finder interface, msn support in ichat, updated front row, like apple tv.
Dunno about the rest, but Front Row seems like a sure thing to update. I predict more integration with the iTMS store and DVD Player. An Apple TV like interface, or at least pieces of that design, would make sense.
A redesigned Finder is a good guess, being this the midway point (10.5) we will see something completely different.
Already commented on the Finder bit, but just pointing out that 10.5 doesn't mean they are halfway through. The A.b designations in software aren't decimal numbers, they're just using the . as a separator between major and minor revision numbers. This is the fifth version of Apple's 10th OS. They could easily go to 10.10 then move right onto 10.11.
An agreement with MS and the Parallels firm to bundle Vista and Parallels with every copy of Leopard. Amazon are slashing the price of Vista, it's practically being given away anyway.
And, Leopard on a Stick - the ability to carry your OS X desktop wherever you go on a USB stick or iPod and plug it into any PC, which will then work like your Mac.
No way they'll bundle Vista... the COULD become an authorized reseller and sell it as an option, but no way it's included with Leopard. I do, however, think they will buy/license Parallels and have virtualization built into 10.5 with fast user/OS switching, full hardware GPU support, Windows in a box, Windows apps running side by side with OSX apps, without the Windows desktop, etc.
Oh, and can you show me where Vista is being massively discounted? I see it on Amazon with a ~5-10% discount, but it's still really expensive...
You can already do home directories on an external drive (like an iPod) but I'm not sure why you'd want to carry the whole OS with you? I'd like to see a setup where I can plug in my 1gb flash drive, though, and have OSX automatically copy the most needed gig from my user files over. All of my preference files, my most recently and often used documents, any apps I pre-designate to be included, any photo albums or iTunes playlists I say should be included (like you top 25 rates, 25 most played, 25 recently played, and your 'last roll' in iPhoto) for example.
MS tried to do something kinda sorta like that with the old Briefcase system, but with the improved metadata OSX has available it seems like it could do a much better job.
Aside from Finder and Front Row improvements, plus what we know about (Quick Look, Time Machine, Spotlight, Resolution Independent UI, etc) my best guess is that they will introduce some new input systems. Perhaps a mouse gestures based shortcut system, or improved voice command system allowing the computer to better understand natural speech.
Hm, I'm going to hold out against hope that they bundle QTP with the OS now, since they are adding more and more media features which need people to be able to do video conversions, etc.
I'm not holding my breath for them to integrate iLife and iWork into the OS. They get $160 or so for each user who buys those, and most people will get one or both. Why would they cut those sales, or increase the price of the OS and cut potential OS updates for those who just want the OS? Makes no sense. Most I can see is them doing a package of all three for a discount. Say $199 for all of them, assuming the standard $129 for Leopard, $79 each for iLife and iWork separately.