Well I think Apple should really improve iOS in the multitasking and notifications areas. I have my facebook set up so each time someone responds to a wall post I make I get a text notification and i can even respond to the post via text. Now of course if I had the iphone I would disable that, unless I had unlimited texting but I know I would get a lot purple pop ups if I don't. Even on the iPad its tough. Your in the middle of a game or movie and BOOM! pop up shows up. Like Apple says, a person shouldn't have to think about it. Have all the notifications be done in the background either via an android style status bar swipe, the lock screen, swipe to the left and have it show up bellow the search box or with in a widget.
As for multitasking. No one has really hit the right nail on the right head. Could Apple be the first with 5.0 or will android beat them with 3.0? What about Web OS? Personnaly I'd like to see what Apple has up their sleves. The current set up is nice, but come on, I shouldn't have to close each app one by one.