I'm suspecting that with a swipe up from bottom bezel, will reveal your App Tray displaying icons for BBM, Twitter and so on...with the ability to "lock" apps in the top such as Weather and Email.
A combo of PlayBook displaying open apps with WP7 and live tiles.
I really hope they do not have multiple pages of open apps, that will get too messy
Quite possibly. Could be.
The reason I said they are minimized, at the beginning of the BlackBerry 10 Preview video, Vivek said something like "So let me open an application" then he said "Not only can I bring it back down"... at this point the video was taken from maximum screen size and brought down to a "2x2" size, over one of the 4 applications.
What if those are a combination of quick launch/widgets? Meaning if you add it to quick launch, it'll be a widget on the home screen.
Or maybe they're widgets, but they're always open. You're right, so many unanswered questions!