The iPhone's lack of ability to run applications in the background (which would be great for IM, music streaming, and location-based apps) is perhaps the device's greatest weakness. Every time anything new is going on in the iPhone world (release of iPhone 3G, 2.0, 3.0, minor software updates), everyone gets all excited and hopeful for background capabilities to become available. Well the WWDC '09 is coming up soon, and the background app rumors are back.
However, all the sources that started these rumors are highly credible. Dan Frommer of Silicon Alley Insider cited some inside sources, claiming that Apple is working on a way to give the iPhone background support. Daring Fireball's John Gruber backed up the rumors, claiming that he has heard similar things.
According to the rumor, applications must go through a much more rigorous approval process in order to have background support. This would make sense, for background apps would hog resources and eat up battery power.
These rumors are in no way certain, but we could expect to get some more info at the WWDC.
[via Business Insider]