Can't wait to watch the chorus of "OMG this is 2010... why can't I type my essay in 64-bit????" make themselves look foolish.
They buried the lede. The problem is NOT that Word won't access more than 2GB of memory. The problem is that Word will not be a Cocoa app. It won't support services. It won't "fit in" with the rest of the system. It will continue to use the ugly segregated and inconsistent Microsoft Office Dictionary instead of the system-wide Dictionary app, etc.
Of all the consequences for dropping Cocoa development, 64-bit is about the least impactful. It's an odd one to choose as the lede in an article about this.