No, but when you get arrested, you can have your defense cite this case in court and see what the court says.
I doubt this rulling will be used to overturn any State gun control laws, since "reasonable infringement" seems to be the key. The courts will always say that whatever regulations, as long as someone can buy a gun, are not unreasonable.
Probably not, each law has to struck down individually. However I would say that if you carry it concealed, you'd be on shakey ground on two counts. First the decision clearly allows for some regulation, and they point to the Miller decision, which tends to indicate that only militarily useful weapons and/or methods of bearing would be protected. Secondly the Texas Constitution does give the legislature the power to *regulate* the wearing of arms. Taken together this might eventually mean you could strap on a Barretta, M1911A1 or H&K USP, openly, but not concealed.
Want to be the test case? Unfortunatly, for reasons I only sort of understand, in general, you can't take a law to court, you have violate it and risk the penalties. There are exceptions though, and this ought to be one of them, but probably is not.