depends on what type of Windows 8 tablet you will be getting. For example, some Windows 8 tablets will be using Windows 8 RT, which is based on an ARM processor (same as those used by Android and iOS devices). Basically its Windows Phone 8+Full MS Office+Desktop Metro UI. While this model will provide long battery life and the Windows Metro experience and apps, apart from full true MS Office, it doesn't have a lot of apps for it yet.
Windows 8 Pro version is another story all together. The new Samsung ATIV Pro, the HP Envy X2, the Microsoft Surface Pro and the ASUS 810 will be using x32 or x64 CPUs, basically the same CPUs in your desktop, and will run desktop version of Windows 8. Basically these are true touch screen computers, and will be able to run any program your standard Windows 7 desktop can, like Adobe Lightroom, Corel Draw, Adobe After Effects, heck you can even play Starcraft 2 on it. Of course this depends on the hardware given, but the MS Surface Pro will be using a core i5 processor and intel HD graphics: powerful enough to run Skyrim on low settings.
As for my opinion, it depends on what you intend to do with your tablet exactly. While a Windows 8 PRO tablet would certainly be more powerful (a dual core ARM chip has barely enough juice to keep up with a single core Intel Atom), and more productive (you can't get more productive with actual desktop grade productivity programs), keep in mind that these devices would be a hell of a lot more expensive than your average tablet. An HP Envy X2 for example, is looking at a probably price tag of $900. These devices are ultrabooks in their own right, with the novelty of being detachable and convertible to tablets.
A Windows 8 RT device on the other hand, has pricing that will be comparable to the current Android tablets, probably running at the $300-$600 price range. But the big factor here is the lack of apps for Windows 8 RT currently. There are only a little over 100,000 apps for Windows 8, and a lot of the mainstream apps like Sugarsync and Dropbox, Instagram, etc don't have apps for the platform for now.
So basically the question is back to, what do you intend your tablet to be? If you intend it to be a laptop replacement, since you are looking to retire your laptop for example, a Windows 8 Pro device is a no brainer better option than any Android or iOS tablet, simply because it IS a laptop with proper stylus support. However if you are looking to complement your laptop and use your tablet as a reader, something to watch movies or play games with while on the move, or basically a media consumption device as opposed to productivity, Windows 8 RT does not offer much yet at this point in time.
