1: On a MacBook Pro 15" 2.66ghz (see apple store) using BootCamp with Windows 7 be able to run games such as, Call of Duty: Modern Warfare 2.
2:Would the MacBook Pro 15" 2.66ghz (see apple store) using BootCamp be able to run MMORPG's such as World of Warcraft ( i know that game can work on Mac anyway, and no, i don't play it) or Maplestory or Ragnarok Online, etc. (to see these games, look them up on Google)
You use Bootcamp Assistant to create a new partition and install Windows on it (don't forget to install the Apple drivers from the MacOS X disc afterwards). This means you're running Windows natively on your Mac, which means that any Windows software will run on it like on any other Windows PC.