I think it would be great to be able to list more than one genre for a game. Some games are really tough to categorize in only one. For example, Mass Effect 2 is both a TPS and a RPG. It's hard to tell if Dead Space is more of a TPS/Action game or a survival-horror. Just two examples that came across my mind... Would be also great for all those action/adventure games out there, like God of War, Castlevania: Lords of Shadow, even Zelda... or there definitely should be an "action/adventure" category.
