It'll probably be a better integrated graphics.That's all good and dandy, except Montevina was also released with a potential for upgrading from the X3100 graphics chipset to the X4500, a supposedly 3X performance improvement. Tell me ol' Stevie won't just opt for better integrated over trying to redesign the Macbook to accomodate a graphics card.
Intel said in 2007 that they would make integrated graphics 10x faster by 2010, so as time goes on there's even less reason to have dedicated graphics in the MacBook.