And that is the reason why "cell phones" are dead, as are "phone networks". Both the iPhone and Android devices are essentially mobile computers that have the capability to talk to a particular legacy network (the voice telephone system). This has been true since the iPhone 3G's introduction of the app Store in 2008.
The iPhone 4 represents something of an inflection point. It's a great piece of technology combined with masterful design and marketing. Apple has both pioneered and become the master of the technology fashion market, which is why it's product launches have become such media circuses.
Apple product launches have almost always been media circuses. Rather than showing new products at CES or some other convention, one among thousands, Apple likes to show new products at dedicated Apple events.
The secrecy helps, too. Most of the industry announces new products far before their launch, giving out specs, photos and demos, so there's no excitement when they are finally released. Apple tries to keep it secret until the last minute, letting speculation and tension build.