From personal experience, I know that Mac runs Windows 7, but definitely not as fast as if Windows 7 was your core OS. Macs just run a virtual machine, which is basically a program running Windows.
Windows 7 is an operating system. A Mac is a computer. A Mac can run Windows 7. The two things are not comparable.
No , you cannot run OS X on a windows machine. Buy a mac
Windows can be installed and run on any Mac (and Ironically windows 7 runs better on a mac than on a PC due to how the graphics are set up)
Yes, in dual boot mode you can run Windows 7 on a Mac.
Mabinogi will work with windows XP and up (that includes vista, and 7 when it comes out). As for the mac, the only known way is to use bootcamp to run windows on your mac.
If you are referring to the operating system then a Mac's default operating system is called Mac OS X. A Mac can be downgraded to run most versions of the Windows operating system from XP to 7.
Snow Leopard and Windows 7 are two completely different types of operating system. You cannot use software written for Mac OS X (Snow Leopard) on a computer using Windows 7 (or vice versa). On a Mac you can run both operating systems so you can run Windows 7 instead of Mac OS X or in a separate window on top of Mac OS X (Snow Leopard) using Parallels or Fusion (See links below).
Boot Camp is about to be updated to support Windows 7 but some older Macs will not be able to run Windows 7. (See links below)
Mac OS X Lion is better than Windows 7 because it is faster, doesn't get viruses, is a lot more secure and in my opinion has a better user interface. It's up to you though to decide which is better. Remember if you get a Mac you can run both Windows 7 and Mac OS.
Windows 7 will work on a recent Mac (See links below).
Macs do not come windows ,only PC's come windows so no a macbook does not have windows 7. However, I heard that Macs can run Windows as smoothly as a PC so you could probably buy windows for it.
Windows 7 by a lot.