I did read the Maryland decision (a cursory overview). If upheld on appeal, the immediate effect on OC is the same as on CC. To do either, currently, you need the same pointless carry permit and that permission slip just got a bit easier to obtain in that you, the applicant, no longer will have to prove a need to carry for self-defense. Everything else that was difficult and convoluted about Maryland's draconian application process unfortunately remains intact.
However, the Judge's opinion noted that technically OC is the right being protected (not CC). The Judge hinted that the Maryland legislature could keep a requirement that an applicant must prove his or her need to carry a concealed weapon, but only if the applicant did not have to do so with respect to open carry. But since the same permit is required to carry either way in Maryland, the State is no longer able to enforce this requirement (so CC gets a free ride).
The Maryland legislature would have to create separate 'open carry' and 'concealed carry' permits if it wanted to keep the requirement that concealed carry permit applicants prove a need. But until then, so long as the only available permit covers both carry options, the law is now less restrictive for both OC and CC alike (assuming the decision is upheld on appeal).
Forgive me if you're still confused. I just gave you the Cliff notes. I don't have the time to get into all the gritty details.
The rest of the opinion was bad, because the Judge wrongly decided that 'bearing' of arms is subject to intermediate scrutiny. Apparently, 'keeping' arms is subject to strict scrutiny but 'bearing' is not, go figure!
Intermediate scrutiny basically boils down to permits, licenses, and hoop-jumping being upheld as constitutional but otherwise the people get to exercise their 'privilege'.
Strict scrutiny hopefully would mean that most (but unfortunately not all) of the 'mother may I have permission' crap will be struck down as unconstitutional. I.e the people will actually get to exercise a 'right' (small 'r' since undoubtedly 'shall not be infringed' won't entirely be true).