Pros: The rapid expansion of the gaming community and demographics
Developers trying new idea in gameplay
Cons: Less sequals to IPs... wait, that's a good thing
More shovel ware (in some ways debatable)
How many copies of the same realistic FPS's have been sold? Homefront, CoD, MW, all follow the same format in multiplayer, just different maps. They may have a few differences but as someone who only plays them on console when at a friend's I couldn't tell you the difference in game since there really isn't one (haven't played Homefront so no knowledge there.) So why pay $60 for the same game time and again for a few new maps and occasional feature, not counting DLC? The "casual" gamers that so many look down will play the quirky random game that actually has innovation (farmville not being one) and will play a greater number of games.
So the system gets some crappy shovel ware, who cares, it doesn't take that much effort to push it out the door, relatively cheap to make and funds itself.
Its not that the casual gamers are dumber, hell to enjoy a simple game is harder to do than enjoy a more advanced game. What's better, a good feature film at full cost that has been remade three times or a series of 5-10 min shorts of different nature that don't cost anything and are mostly good? Claiming that people who find enjoyment in social games are dumb is a highly elitist, narcissistic and backwards view. I'm gonna wrap this us, the new causal market is helping the industry regardless of the hardcore elitist taking his blinders off.