Both issues are being addressed in iPhone OS 4.0, which Apple announced overnight.
A beta release is now available for developers, and Apple says "iPhone OS 4 will ship this [northern] summer for iPhone and iPod touch, and for iPad in the fall."
Apple's objection to unrestricted multitasking on the iPhone has always been that it would adversely affect battery life. However, officials claim that the seven multitasking services in iPhone OS 4.0 allow tasks to run in the background "preserving performance and battery life."
The seven services cover background audio, VoIP, background location (eg, so a navigation app can continue to provide directions while another app is running), push notifications (received even if the target app isn't running), local notification of events and alarms, task finishing (in case the user quits before processing has completed) and fast app switching (return to apps in the state they were left).
What else is new from a user perspective in iPhone OS 4.0? Please read on.