Since I know several lawyers play Vintage, I figure I would ask here: suppose WotC prevails on the patent claims (which seem to be where Hex is most vulnerable): if Hex does not sell any copies before the mtg patents expire in June, what's the worst remedy that Hex might expect? Isn't the patent claim a moot point? Or is there a "fruit of the poisoned tree" principle that prohibits Hex from doing R&D/beta testing using patented inventions?
And you think lawyers who play Vintage are going to give you legal advice on this topic? No sir.
I will say this much. Money damages are not the only kind of remedy a court can impose. A court can also give injunctive relief. That means the court can order someone to do something or stop doing something. If the person ignores the court's command, they can face fines, jail time, or other damages.
EDIT: And, as a player, I can say this, too. Wizards, take a look at the Hex client. Now look at MTGO. Back to Hex. Back to MTGO. Do you notice how one of these things looks like an actual video game and the other one looks like someone installed AOL from a series of floppy disks? Do you think you might want to do something about that rather than filing lawsuits? Just saying.