It may turn out to be a huge win. This decision was made in U.S. Federal court. I would guess that the state of Maryland will appeal, but they're now fighting an uphill battle. If they don't appeal or the decision is upheld it will have implications for all states since it was a Fed decision.
The first state that comes to mind for me is New York. I have a brother who lives in upstate NY. It's been awhile now but he had to go through a somewhat similar process to get a handgun as those in MD. As I remember what Ken told me was that when it was all said and done, a judge had to approve him before he could buy the revolver he wanted. And again IIRC, the judge could deny the permit and give absolutely no reason for the disapproval.
This sounds similar to the MD law where the citizen had to come up with reason to justify the purchase. The judge and rightfully so has now said our 2nd amendment rights are not conditional. I would have to imagine the NRA will be all over this and filing suit in NY and any other state with similar laws.