Unlike Windows Mobile and other smartphone platforms, iPhone OS 2.x runs applications one at a time. The exceptions are Apple's own phone (voice) software (naturally), email, and iPod (music playing). A number of sources including the Silicon Alley Insider item linked below...

Apple Serious About Background App Support For iPhone 3.0

...have speculated for the past couple of days that this will change with iPhone OS 3.0.

I've got two very divergent feelings about this possible development:

1. It is about time! Other major smartphone OSes are multi-tasking. Why not the iPhone?
2. This is the road to end-user experience disaster as thousands of apps with possible process and memory management issues collide on millions of iPhones and iPod touch-es.

Your thoughts?