Charles, I think you missed a point in the dicta from Heller. The meaning of the "regulation" verbiage is that the law may regulate the mode of carry, but may not ban carry outright.
Ohio is a good example. Even before Heller, the Ohio supreme court decided a landmark case based on the Ohio state constitution. Ohio had a law banning concealed carry. I don't recall the name of the case, but the state supreme court ruled (correctly) that the state constitution guaranteed a right to bear arms. Therefore, if the legislature chose to ban concealed carry, by logical consequence open carry must be legal.
This decision lead to a series of open carry days, and the legislators decided they didn't want to see so many people openly carrying guns so they enacted concealed carry legislation.
California, until recently, was operating under a bastardized variant of this concept: open carry was legal if your gun wasn't loaded. While allowing only the carry of an UNloaded weapon probably would not meet with success now that the SCOTUS has ruled that the 2nd Amendment is about self defense, that was California's law and the state would no doubt argue that they hadn't banned carry, only regulated it.
But now they've eliminated the escape clause allowing the open carry of an unloaded firearm. So now the California "may issue" permit system is ripe for challenge.