This could be big, or it might not be. If these guys win the case, this could have BIG ramifications in regards to game stores (AL to people that just demo or run games) to conventions (some conventions use volunteers, some booths are entirely volunteer driven at times), to maybe even websites like ENWorld (though that's reaching a little far, it could happen).
It boils down to what is volunteer and what is not, and what is given freely, and what is expected to be paid for.
If you know about me, I obviously would support WotC's side of this. I find it a dangerous precedent that is being sought and I am wondering if it's merely a money grab, or something more. Other volunteer groups have their members wear a certain type of clothing standard, have set hours (afterall, the hospital gifts shops, in theory, at the prices they charge, are NOT entirely non-profit, though utilized BY a non-profit, and are normally run by volunteers).
Despite my background, I can understand the pursuit of the case by some people, and why some would be disgruntled at how some of the judges are held accountable and utilized, however, in any organization where you must make judgement calls (for example, volunteer coaches who also referee soccer games for the little ones in many of the city leagues) which adhere to certain standards and are held accountable.
I think if it were simply up to a judge, it might be considered a frivolous lawsuit and that the Hasbro/WotC lawyers could convince a judge of why it is frivolous.
If it goes before a jury, that's much more debatable. Jury members may not understand how the Magic system works, how the tourney system should work, and what is fair to players, stores, and cons. A Jury trial could favor these guys if it isn't tossed out. I expect it will prey upon the expectations that the Jurors are not familiar with the system and thus be sympathetic to the portrayal of the idea of abusing the relationship between WotC and the MtG judges.
I don't think it so much relies on which court it goes to, as much as who the jurors are if it goes before a jury.