Microsoft on Thursday released the final preview version of its upcoming Windows 8 operating system ahead of the commercial release. The new version was released only as an upgrade to earlier previews so if you don’t already have the old version you’re out of luck. The final preview comes just as Acer, Toshiba and other OEMs are planning to unveil new Windows 8-based tablets at the Computex show in Taipei next week. Apple CEO Tim Cook, however, used the occasion to do some trash talking of Microsoft’s strategy of using the same OS for both tablets and PCs. “Products are about trade-offs. And you have to make tough decisions, you have to choose,”  Cook told the D 10 conference on Tuesday.  “The fact is, the more you look at a tablet as a PC, the more the baggage from the past affects the product.” Let the smack downs begin.