We should remember that the title is "64-Bit
Desktop Computing Will Be Mainstream In Two Years.
This is certainly not mainstream.
It's a marketing ststement .....
Fair enough, but I think with the popularity of the AMD64 chips, there will be mainstream 64-bit PCs earlier than Bill Gates thinks.
I'd argue that AMD64 is mainstream now.
My next home machine will have an x86-64 in it. Or two, maybe.