Very few laptops on the Windows side use a truly swappable graphics card, and them it's usual enthusiast machines like those from Alienware. The Intel HD3000 in the 2011 13" MBP lineup is comparable to the nVidia 320M it replaced, but both GPUs were integrated onto the motherboard instead of modular in nature. Even the ATI cards in the 15" and 17" MBPs are soldered onto the motherboard and can't be swapped out.
That being said, the upcoming MBP refresh should see increased performance across the board. The Intel HD4000 is the successor to the HD3000, and it is capable of running Skyrim at a playable framerate, which means it's a nice step up from the current crop of Intel integrated GPUs.