Probably the single most reason to buy the iphone4 is the availability of the siri app. Apple realized the magnitude of AI technology and were quick to monopolize it by acquiring it in early 2010,way before it could be distributed to rivals Android or RIM.
Probably the smartest move by apple however was to get it off the appstore a few months prior to the release of the iphone4s.They realised this was going to be a huge for upselling their newest golden goose,so why give it away free, if it can be bundled with another iphone and sold for $1000 a piece?
Proud owners of the 4s love thier new prized possession. Some claimed that siri on iphone 4 app gave connection errors,probably due to the fact that it was over accessed by millions in the first few hours of its release. The overall experience of the personal assistant that now integrates with the IOs 5,rather than masquerading as an app, will be looked upon as our first tryst with AI. It does draw a crazy comparison with “skynet”, in a mildly humorous sort of way of course, but im guessing it wont be long before siri “takes over the world”, in more ways than one.