Actually, the NCAA games don't sell near the volume that the NFL games do. Also, a huge hassle involved in the NCAA games is that the game maker has to license each school individually, it's a huge pain. And, if you look at the NCAA football games out there, they are usually the previous-year's NFL game with college uniforms. This makes the NCAA game cost effective. I highly doubt it will be cost effective for a publisher to make only an NCAA game and not the NFL game.
And, c'mon, who is going to buy an XFL game, no matter how great the game is? Midway announced in response to this news that they will still release their Blitz game, but it will be Blitz: Playmakers, based on the ESPN series Playmakers. Anyone going to want to play this one? Maybe a couple people, not the hundreds of thousands that will flock to the new NFL game.
Now I'm not upset with EA. Madden is a great game. And it was the NFL that approached video game publishers with the exclusive license deal. No matter who had won the deal, be it EA or Sega or whoever, I think it would have been a bad thing. I think one of the reasons Madden is such a great game is that, every year, they had to make it awesome so that it would be better than Sega's ESPN game. And Sega had to make their game better every year to compete with Madden. But with Madden being the only game it town... what does EA have to care now about making the game better? They could do simple roster updates and they would still see massive sales.
Just my opinion. As far as the NFL is concerned, if they had to pick one publisher, I think they made the right decision. I just hope this deal doesn't hurt the NFL brand in the long run, and I hope Madden does make improvements every year.