I can only say that no one who knew what they were talking about made those assertions, Microsoft certainly didn't. Windows XP Professional x64 nrun 32 bit applications using a subsystem (WOW64), in the same way that previous versions (NT, 2000, XP) used WOW to support 16 bit applications in an emulated mode. Actually, x64 is Microsoft's second 64 bit OS. They had a version of windows for Intel's Itanium. Using emulation to support a previous architecture is not uncommon. Usually, you take a performance hit, as in Itanium's 32 bit emulation mode. AMD's extention of the x86 architecture avoids that problem.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken