i think crossovers are possible, but i also think that as technologies deepens, so will the genres evolve into newly allowed territory... pehaps RTS games that allow u to coordinate from above and once a battle plan is set u can go headlon into the action (didnt mech commander try to do that? i dont know i never played it?)... or smarter RPGs where every action u make influences the final out come... time based missions where if u dont make it to a castle in enough time (by leveling so u will be a god compared to the boss) then the critical point has passed and u cant save the kingdom.