I'm hoping a developer will make their own Expose/Spaces clone.
We have BusyCal to replace iCal and although BusyCal could use a UI upgrade, at least it is feature complete, easy to use and doesn't look like complete ass.
There are okay Address Book clones for those of us that don't think our computer should be flipping through pages.
TotalFinder gives us a Tabbed Finder.
Sure, you can make MC work for you, but I never had to make Space/Expose work for me, those things always just worked without any thought or effort. I move my mouse to two corners and I could see absolutely everything at once, move windows around, only deal with one or two animations, etc. Simple, direct, clear. MC can't show you everything at once, App Expose takes you out of MC, etc.
All we really need is a good Windows/Content management system back and it looks like an outside developer will have to do it because it is clear that Apple without Steve is not capable of thinking through all the little details.
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Mission control was like the old "see all windows" Exposé, which I think one of the commenters here is complaining about. You can also do the "single app" Exposé.
Mission Control is close to "see all windows" but the windows overlap, obscuring the content. If you have more than 2 windows then everything is obscure and sometimes entire windows are obscured because they are smaller than others. You can then do App Expose, but that takes you out of Mission Control, making it so you can't move windows around. So you then have to go back into Mission Control to move the window to another Space. Heaven help you if you want to move 5 windows around.
Also, Mission Control cannot show you everything at once. Forcing you to remember which space you content was on and/or which application you content was on. Not that big of a deal, but annoying considering you never had to bother remembering anything about your content beyond its basic appearance.
Overall, I find that Mission Control requires a lot more work to do simple things as compared to 10.6. I would gladly put 10.6 on my Macbook Air if I could find all the drivers. Then I could just wait until an outside developed releases an Expose/Spaces clone.