Just saw this in engadget...I posted this in another forum but it should have been here:
I like the idea of 2 windows or 4 max fill up each quadrant. I feel multi windows makes for better functionality with multitasking. For example say your waiting at the airport for your flight, your watching a live football game on some tv app, you also have a browser opened at the same time to check your fantasy league all without missing the feed. Its halftime and you decide to play some angry birds in the mean time. You still have the fantasy league opened to check on how everyone else is doing and the tv opened to make sure you dont miss the start of the 3rd and all are viewable simultaneously. Then you get a call or video call from your friend, angry birds is paused and everything else are muted. You talk as the 3rd quarter begins and off the bat and onside kick is recovered and ran for a touchdown. The play was not missed visually and you guys go on talking about the highlight. You never lose your place, you know where everything is and nothing is missed. You would also have the option to set focus on a window or go to cards modes, or back to quandrant mode, etc. Theres enough screen estate to do this and it would be incredible.
There would need to be some type of app priority though to have the call/video call take charge of the speakers to bring it to the foreground and mute everything else. Other instances without the call would be optional to mute or have sound from each window.
...I think 4 max is ideal, if there are more windows opened you can use the gestureand a key combo to select for simultaneous viewing, an option in the app, or something....
BTW, when in simultaneous mode apps would scale down to the handset version like email and pic viewer per say.
Ittiam shows off four-way 720p HD video conferencing using Android, OMAP 4 (video) -- Engadget
quadrants would be useful.