In spite of the iPhone's in-your-face success, it still lacks one feature most other smartphones embrace as standard - the ability to run more than one application at a time, with the unused process hiding in the background.
Apple has long said it doesn't want its pride and joy to use PC-like background processes, seeing them as a battery-suck and a security liability if left running unseen.
Push not enough
To that end, it has made very public efforts to instead allow the iPhone to quietly receive notifications from the network for some services and to push notifications, such as email or IM alerts, to users even if they're not using the associated apps.
Rumour has it that either any app wishing to run in the background will have to be pre-approved by Apple or that there will be a limit of two background applications at a time.
These measures could reduce Apple's concerns, particularly on battery life, but until we get official word on the next-gen iPhone we'll just keep our fingers crossed.