I think that ever since EA was the only brand that could produce NFL Games, they stopped trying to make the game as good as they possibly could. They were getting better each year when they were competing with 2K Sports, but now they don't improve nearly as much each year.
I've run into people that still play 2K5 with updated rosters. There are still sites out there dedicated to updating the rosters, including draft picks each year. I can't ever play an older game, because frankly, I'm a graphics junkie, but I may try it at some point.
On a side note, I changed the 'sliders' around on Madden 2011, and it's much better. I've heard they're going to make the 'audible pad' or whatever it is, optional. I turned off 'Gameflow', and I'm starting to like it a bit more.