James Portnow @ Gamasutra: "To date the 'casual' market has targeted the 'casual' gamer -- but the question arises: "Do the 'hardcore' need casual games as well?"
Y'all know I get uppity about definitions, but here's one term really does need some defining: "Casual Game". Who knows what "Casual Game" means these days? Unfortunately, I'm not really qualified to make a sweeping definition of "Casual Games"(I know there are some guys at PopCap that have put a lot of thought into this, and I encourage them to share those thoughts with the rest of us!) but I'll give you a little bit of the reasoning that led me to pen this.
This year, Braid won the Interactive Achievement Award for best casual game -- but by the definition I've been running with, it's not a casual game. So I started looking at media use of the phrase "casual games." It's all over the place, but I've really only seen one constant: at this point, casual games are defined in the popular media as "non-violent games," and we've begun to adopt this definition."