Pandora, the popular Web-based music service, will be able to play in the background while other applications are active in the foreground. Pandora CEO Tim Westergren says the company added multitasking to its applications in about a day.

Background music is welcome, of course, but being able to use multiple productivity apps at the same time as receiving a Skype call when it is not in the foreground is much more significant.

There is a potential catch, however. Active applications use significant amounts of power, and it is not immediately clear what changes, if any, Apple will make in upcoming hardware to solve, or at least mitigate, the problem. Steve Jobs downplays the issue, claiming that apps running in the background usually aren't using very much power.

Still, business users will be very unhappy if their iPhones, which now last about a day on a single charge, need to be plugged in more frequently.