I let out the biggest “finally!” today during the Lion preview event, when Steve Jobs said one of the things Apple has learned from iOS apps that they are intent on bringing to Mac OS X apps is stateful pause and resume.
In the Mac environment, with a more specific sense of what “quitting” an app is, it’d be more like saving and restoring the app’s state than pausing and unpausing when you switch apps in iOS, but the effect is the same. No more untitled document syndrome, no more being told you can’t restart your computer because an app needs attention before it can quit, no more crashes causing massive data loss (one hopes… although one also wouldn’t expect Adobe to jump aboard this new technology with particular fervor), just the illusion seamlessness and stability.
Well-behaved apps do this already, as there’s nothing stopping developers from rolling their own auto-save/restore/crash-recovery scheme. But with Apple stating it as a clear goal for 10.7, leading by decree and by example, we can hope it’s adopted across the board in relatively short order.