In the source article Paul Thurrot writes, "According to my Microsoft sources, the current internal Vista build is now 6.0.5920.16384. Whenever Microsoft finalizes Vista--and I'm told it will be on or before November 8--the company will artificially increment the build number to 6000, as in "6.0," which is Vista's version number (aka Windows 6.0). Come on, admit it: You knew Microsoft would pull something silly like that."

Source: Windows IT Pro