Thanks, AATW. You’re on a roll. Anyway, this is significant because it’s a direct swipe at Microsoft’s real cash cow: Office. They might lose some people to OS X, but most of them still buy Office for a few hundred bucks. And nearly every business computer has Office for another few hundred bucks. Microsoft may not react strongly to Windows challengers, but you can bet that they’ll spectacularly freak out if Office is threatened.