Every year there's a new Madden game that comes out that essentially just redoes the stats on each team, maybe add a new game mode and feature. The problem here is that a lot of games are making new changes and adding new features through DLC (Downloadable Content). If they just made one Madden game and each year just had DLC that made the necessary changes to the teams and maybe throw in some new modes to play this would be much easier to distribute to the masses and could probably be sold cheaper to encourage more sales.
Bethesda has always had new DLC for their games over the years such as Elder Scrolls: Oblivion and Fallout 3; adding new levels, new equipment, more quests, minor bug fixes, etc. Valve is also known for releasing new DLC for their games and releasing them for free. They are planning on adding a new mode, more maps, and new versus maps to play on for their popular multiplayer game Left 4 Dead. All for free. Online sales and downloads have been rising especially with Valve's online store service, "Steam".
Other developers are doing more and more DLC for their games so there's no reason why EA can't do this so we don't have to have Madden 2000-2009 filling up our shelf space. It's not just Madden though, all the other yearly sport games do it too, so come on dev's! let the next generation of sport games be DLC available