In an advisory published on Gartner's website last week, research VP Michael Silver said administrators should ignore any suggestions that Apple's move to Intel processors will expose the system to security vulnerabilities.
Silver said in the advisory: "All users should ignore any hype about the possibility of exposing the Mac OS to more viruses or worms. The Mac software will be located on another partition within a different file system; thus, running Windows on a Mac will not expose the Mac software to more malware."
However, one should note that if Apple's move to Intel CPUs and the provisioning of Apple's Boot Camp software leads to Mac OS being more commonly used, this will likely encourage cyber criminals to increasingly target the OS with malware. XP is a main target because of its popularity, and if Apple's OS becomes more popular, it will be more targeted too.