FWIW RW back in post #5 probably has it nailed. California could come up with a 3 week tour that could rival the Big 3 in difficulty ut no one would want to ride lke that during the early season.
ToC could move to the summer and try to compete with thee Big 3 but their chances of drawing top talent from the Euro tours is probably pretty close to zero.
It seems like they've got a nice thing going and hopefully it'll continue to grow.
I'm more than a bit worried about the Tour of Georgia snce that's the one within easy driving distance for me.