They didn't have a use for a front facing camera, or could make it easy enough to use, so they didn't include one. Now they have one because they were finally able to implement video chat in an easy to use way (Face Time).
They didn't have copy and paste until they figured out how to make it as elegant and easy to use as it is.
They didn't include 3G in the original iPhone because it would have affected battery life too much.
They only introduced the SDK once the API was in a usable state and they got the necessary documentation and infrastructure in place to support 3rd party developers.
Face Time currently only works on WiFi, but from what I read about it it actually works for Joe Average. On other phones you have to be a geek to figure out which software to install and how to set it up.
For some people it is certainly valuable to have barely working bleeding edge features on the phone, but for the 99% of users out there who're not interested in tinkering with their phone Apple's approach makes a lot more sense, IMO.