[solipsist]

Since I've written this gigantic post, I've learned a few more things about the process[1][2] and have changed my stance for the most part.

In a nutshell, the multitasking tray is simply a way to access apps recently used. The tray sorts itself in an MRU order and removes apps once enough time has gone by without being used. Apps in the tray can either be running or not running, depending on whether or not they support multitasking.

The effectiveness of MRU order and the need for another hardware option can still be argued, but I think you have at least helped me settle what the multitasking tray really does. Thanks.

[1] http://news.ycombinator.com/item?id=2065582 [2] http://daringfireball.net/2010/04/mobile_multitasking