Deep Geekology: Do IPAs Vary By Region?

Ruminating from Leeds, Ghost Drinker ponders:

In my latest IPA post, there was quite a call for West coast and East coast IPAs from America to have their own style categories. I can sort of see why. I can see a big difference between English and Scottish Ales and they're only a few hundred miles apart. I guess it makes sense for Ales that are a few thousand miles apart to be a little different... 

He then asks for examples of classic examples of East and West Coast IPAs as a way of illustrating the difference.  I have thoughts on this, but I thought it would be more interesting to elicit yours.  The questions are these

1. Do different regions of the country make IPAs differently?
2. If so, what are the differences?

I will up the ante by saying opinion is not enough.  Show your work by highlighting high-profile IPAs that bolster or refute the case for regional variation.  Anyone can riff with opinion, but is there a data-based case to be made?