Nothings outselling the iPad for the next year. However beyond that, the Windows Tablets are going to surpass the iPad. The value proposition for Current Windows users and Enterprise customers is very high. Windows on a Tablet allows you to keep all the software you've spent Thousands of dollars on and transition to metro apps that in theory should increase your productivity with them being developed to help users accomplish a series of small specfic tasks. The cross polination with the XBOX division and Windows Phone 8 make the Windows Platform pretty compelling. Home, Work and Play models the way people live pretty closely and Windows now has basically the best experience on at least 2 out of the 3, based on feedback and ratings.
The Pro version is interesting because in theory it's supposed to be an Ultrbook and a tablet. However, my current plan is to get an Envy Spectre and Windows RT tablet. As a developer, it's hard to put you hopes and livelyhood in a device that was designed first and foremost to be a tablet. It's also hard to really write code and work in photoshop on a 10 inch screen. Writing code on a touch type keyboard could be awesome, but the standard keyboard experience is a known entitty. RT tablets are all about consuption and I'm very interested in seeing what Nokia has in the pipeline now having seen the surface. A Surface or Lumia RT tablet should garner the same oohs and ahhs as the iPad if not more.
Microsoft was smart to set the Experience and Hardware standard for Windows 8 Tablets. Every 3rd Party vender just scrapped those budget designs they were recycling from Android. Unless we see designs from 3rd Party venders that excite consumers like the Nokia Lumia 800/900, consumers comitted to buying a windows tablet will just choose the Official Microsoft Tablet. That will hurt the price parity in the consumer space with Apple and Google initially, but from a perception standopoint, consumers will view the Windows Tablets as the creme of the crop. Creme of the crop hardware plus the ability to recycle my software is the formula for market share takeover.