This is not just a bug in some feature that used to not exist, this is a regression that Apple took upon themselves completely consciously.
"Full screening" existed before Lion. It worked fine. You could for example run Quicktime or iTunes full-screend in one monitor and do work on another. Then, in Lion, solely to be able to market it as a new feature, they tweaked it to conflate full-screening with spaces and broke the feature for many people that had been happily using it for over 5 years. They could have just added the existing full-screen behavior to the iLife and iWork apps and things would have been fine. They didn't. It is clear that Apple knew they were going to break this feature for people, and did it anyways. (For example Quicktime used to have an option in preferences whether to black out the other screen or leave it usable, this preference was removed in Lion -- someone literally went in and deleted functioning and better code -- this was not some "whoops" mistake).
On top of this, what is particularly infuriating about this is that it hurts the people that have invested heavily into Apple by purchasing more than one monitor, many times expensive Apple monitors. It is completely acceptable and expected for people to get angry about regressing their monitors' abilities. Maybe its not a show-stopper for you, but for people who have spent a lot of money purchasing monitors, and had an existing workflow that functioned for YEARS, to all of a sudden lose it to a paid upgrade is 100% what I would call a show-stopper. Especially because it has been a year now and it is clear Apple just doesn't care about this.
"Well Apple is just more focused on the single screen experience now and you're just not important anymore". Bullshit. They repeatedly advertise, and continue to advertise the expanded capabilities of, multiple monitors: http://www.apple.com/displays/. The Air + Secondary Display is widely used, and most the laptops now support more than one external monitor. Thunderbolt even added daisy-chaining of monitors. This adds to the absurdity and schizophrenic nature of the issue: many pros use multiple monitor setups, and yet Apple went into the pro apps and degraded them to now only work with one monitor in full screen mode.
Of course, this shouldn't be surprising, its really a microcosm of the entire Lion release: very little to no new functionality and instead unneeded "tweaking" of existing behavior. We paid to have our scrollbars made to look like iOS and have everyone learn to "reverse" their scrolling, for Safari to perform the worst its ever performed (I don't think I know anyone who uses it anymore), and to have full screen broken.
"Full screen" mode existed before Lion (10.7), but prior to 10.6 the API did not exist. There are actually three ways to do full-screen in OS X:
1) Use Core Graphics to capture the display,
2) Manipulate window properties to get the result you want, or
3) Send the toggleFullscreen message to a window (10.6+ only).
Let's ignore option #1. It's primarily useful when you need to change the screen resolution without affecting other applications.
You say that the feature was deleted from Quicktime, but that's not what happened. Quicktime 7 and Quicktime X have different code bases. Quicktime 7's fullscreen functionality predate the current fullscreen API, and so there's a chunk of code in the Quicktime 7 player itself to futz around with window levels, types, desktop modes, and animate the whole thing. The Quicktime X application uses a different framework for video AND a different framework for the GUI, I doubt that you could bring much code from Quicktime 7 to Quicktime X.
Quicktime 7 used the old Quicktime library with Carbon. (So the API it was using to go fullscreen is even deprecated!)
Quicktime X uses the new Quicktime framework with Cocoa.
I myself have implemented the "nice" fullscreen technique, it requires some extra code but allows you to decide whether to allow other applications above yours.
I don't care if the feature broke because QT 7 and QT X have completely different code bases or because they removed the correctly functioning code. Either way it's broken and it's really fucking annoying.
"Full screening" existed before Lion. It worked fine. You could for example run Quicktime or iTunes full-screend in one monitor and do work on another. Then, in Lion, solely to be able to market it as a new feature, they tweaked it to conflate full-screening with spaces and broke the feature for many people that had been happily using it for over 5 years. They could have just added the existing full-screen behavior to the iLife and iWork apps and things would have been fine. They didn't. It is clear that Apple knew they were going to break this feature for people, and did it anyways. (For example Quicktime used to have an option in preferences whether to black out the other screen or leave it usable, this preference was removed in Lion -- someone literally went in and deleted functioning and better code -- this was not some "whoops" mistake).
On top of this, what is particularly infuriating about this is that it hurts the people that have invested heavily into Apple by purchasing more than one monitor, many times expensive Apple monitors. It is completely acceptable and expected for people to get angry about regressing their monitors' abilities. Maybe its not a show-stopper for you, but for people who have spent a lot of money purchasing monitors, and had an existing workflow that functioned for YEARS, to all of a sudden lose it to a paid upgrade is 100% what I would call a show-stopper. Especially because it has been a year now and it is clear Apple just doesn't care about this.
"Well Apple is just more focused on the single screen experience now and you're just not important anymore". Bullshit. They repeatedly advertise, and continue to advertise the expanded capabilities of, multiple monitors: http://www.apple.com/displays/. The Air + Secondary Display is widely used, and most the laptops now support more than one external monitor. Thunderbolt even added daisy-chaining of monitors. This adds to the absurdity and schizophrenic nature of the issue: many pros use multiple monitor setups, and yet Apple went into the pro apps and degraded them to now only work with one monitor in full screen mode.
Of course, this shouldn't be surprising, its really a microcosm of the entire Lion release: very little to no new functionality and instead unneeded "tweaking" of existing behavior. We paid to have our scrollbars made to look like iOS and have everyone learn to "reverse" their scrolling, for Safari to perform the worst its ever performed (I don't think I know anyone who uses it anymore), and to have full screen broken.