4 of 6 EA games just came out for Macs. Unfortunately, they will not work on Macbooks. All Macbooks have intel GMA950 integrated graphics cards. Apple.com specifically says: "Note: This game does not support the GMA950 integrated graphics card. " These 4 were released by EA games, not EA Sports division, hopefully it will be different for Madden and Tiger.
I did find, in a different forum, that Madden 2007 for Windows will work with the GMA950. I don't think that they really changed the game much, so it might work. I am in the same spot. I want to play Madden, but I have a Macbook.
If if won't work, install bootcamp and buy Madden 2007 for Windows.