It's somewhat interesting (or just entertaining) that things large corporations have been doing for ages are gaining new attention because we can throw Apple's name into the mix.
Not really. Companies of every size have been taking advantage of stuff like this for decades. Stuff like Delaware's corporation laws [1] are pretty well known. It's common sense, really. Why would anybody pay more taxes than they had to?
Unless I'm grossly mistaken, there's no tax benefit to incorporating in Delaware. Their franchise tax is actually pretty high. The reason to incorporate there has to do with reducing legal costs, AFAIK, which is a separate matter.