If I were in California, I'd be quietly grateful that my Supercharger network is so far ahead of other states and wait patiently while more get built all over the place. Yes, California needs more than what is currently out there... but do you really think further Supercharger build-outs in California should take priority over the 35-40 (or more) states which currently have no Superchargers at all?
Unfortunately, Californians probably are calling for superchargers to make a SF to Seattle trip possible (which is why Tesla is planning SC in the Pacific Northwest next).
In terms of most traveled roads (ignoring for the moment Model S market share, which probably also plays a role in supercharger distribution) here's the data:
http://www.fhwa.dot.gov/policyinformation/tables/02.cfm
California ranks pretty much #1, and Tesla installed SCs here first.
NY, NJ, and DC is also pretty far up there which is why Tesla installed superchargers there next.
Next area is Houston/Dallas in Texas.
Specific cities high on the list include Chicago, Miami, Atlanta, Phoenix, Las Vegas, Denver.
And from recent news it seems SC rollout is following exactly the road usage data posted above:
We will be adding Supercharger coverage in many areas over the next three to four months, installing our first Superchargers in the Pacific Northwest, Texas, Illinois, and Florida with additional coverage in the Northeast and California.
http://www.teslamotors.com/blog/inside-tesla-032113
From the data, I predict the next routes will be:
I-45 between Houston and Dallas/Fort Worth
I-75 between Atlanta and Miami.
I-10 between LA and Phoenix
Not sure for Chicago and Denver.