When people complain that the iPhone doesn't do multitasking, that doesn't necessarily mean they're desperate for a bunch of apps to run on their iPhone simultaneously. (Sometimes they do; more on that in a minute.) No, a major productivity hurdle on the iPhone is the fact that sometimes a user needs to use several apps to perform a task--for example, switching among Mail, Safari and Notes while researching a memo--and switching rapidly between apps is just not something the iPhone handles well. You have to press the home button, find the next app among your home screens, then launch that new app, navigate to where you want it to be, and then repeat the process to switch back.
So when Apple says it's added multitasking to iPhone OS 4.0, one of the big things it's added is actually smarter app switching.
