Scenario:
Welcome area, your history window is open so you don't miss out on any of the chat in the welcome area when someone compliments you or asks a question. Your IM window is open while you chat with someone in private about well... anything. Your map as small as you can make it sits in prime real estate blocking your view of someone who flew/walked into that corner of your screen. And your inventory window is open while you search for that object or texture to give to someone.
Lots of windows... and some of us have a new fangled video card with two monitor ports and an extra unused monitor kicking around somewhere or run SL on a laptop with Windows XP's multi monitor support.
It would be nice to throw some of the windows over to the other screen like the map and build/edit tool window, history window, IM window, and inventory window. No matter the size of the viewer window it's never large enough for the multitasking resident. ^^
