The only way to expand the gaming market more is to get more people into gaming. As was said, the new people going into the gaming market will be casuals, thats just how people start, no way starting hardcore. This is just the casual phase that we all have to go through and just wait when the market expands so much that those casuals will then turn to hardcore gamers.
At some point then, there will be a thinner line between casuals and hardcore gamers.