I think it all comes down to the $100-$50 price cut that never happened. Exclusives aren't the issue, paying for Live is not the issue either. It all comes down to the system pricing imo. The PS3 and the Xbox are otherwise too similiar to point to any other cause.
Most casuals only care about the big titles (your Call of Duties, Battlefield, Assassins Creed, Grand Theft Auto, racing games, sports games, ect.), and many "hardcore" gamers like myself predominantly play the big third party games as well (at least for me I would have only maybe 1-2 exclusive games in my top 10 list this generation). Exclusives outside of mega huge franchises (Halo, Gran Turismo, God of War, Gears) are not great justifications to buy one console over another generally ... doesn't make sense to buy a console for just one game unless you are a die hard fan that has to play it.
The Xbox should really be at $250 or $200 for the model with the hdd/kinect and $199 or $150 for the 4 gig model. The PS3 can justify the higher price point with a larger hdd and a bluray player built in. The Xbox can not.
