" I will personally hi-five you if I see you, because MTG is probably the best game ever made (except for Battlestar Galactica the board game) " and of course chess, the original strategy game that got owned when Magic came out :p
Did Magic take a bunch of market share from chess? How about Go? It has the interesting distinction of being one of the few games to not have a decent AI built to play it yet. At least that what Wikipedia tells me. The AI in Magic games has traditionally been pretty crappy as well.