They still have to target the hardcore, but going forwards I do feel casuals are becoming more and more important.
Simple random anecdotal example, from a girl I recently booked for a shoot. I look at the friends I have that are hardcore gamers and some buy a few apps, but most only stick to free ones. Yeah they are playing the latest core game, but they are still rocking an iPhone 3gs. They basically buy a console and that's the extent of their hardware purchases, and they buy the occasional 'hardcore' game and play that. Contrast this to the last girl I filmed. She has the latest tablet, filled with apps. She has the latest phone also filled with apps. She plays games too, and since she doesn't have pay tv she subscribes to all the usual suspects for her tv and media watching on her digital devices. She clearly spends lots of money on digital purchases and related hardware, as she has lots of disposable income. However Microsoft aren't getting a penny of it because she doesn't own a console. I asked her why just out of curiosity, and her exact answer was "All they have is killing games." Right or wrong that's her perception of game consoles, and because of it this girl who spends more than 6 of my hardcore gamer friends combined is spending her money elsewhere.
Another real but anecdotal example was a girl that was actually a gamer girl. She plays games like Fallout 3 and Skyrim, but she also plays lots of casual type games and like the girl above spends lots of money on digital purchases and digital hardware, far more than your typical hardcore gamer. This girl had a ps3, but the only thing she did on it was play those hardcore type games like Fallout 3. Outside of that her activities shifted to other devices like tablets and phones and that's where she spent the bulk of her money. So Sony got a bit of her money on the hardcore games she played, yet didn't see a penny of all the other money she spent on other devices because they didn't provider her a platform she wanted to be on for those activities. Another monetary opportunity lost.
I can't help but imagine that Microsoft would and should want a piece of this lucrative type of consumer who while considered 'casual', actually still spends a boatload of cash. Yeah keep the hardcore, but there's no reason to me not to target casuals more and more going forward as I feel that is a larger money pool to tap. Right now they are just spending all their money elsewhere, given that Microsoft has computers, tablets, phones and console it seems to me they are in a good position to try capture this type of consumer.