x86 hardware, and especially Intel hardware, will add significantly to the cost of the tablets.
The second “obvious” reason why the tablets will be so expensive is because Microsoft is unwilling to disrupt its own business model. This is exactly the reason why instead of using WP7, a pure “modern” OS, they want to use the “full” Windows, even though it gives them very little benefit where the real market for tablets is – the ARM market.
This is also why Microsoft is afraid to go “full-touch” and “Post-PC” with a new OS like WP7, and instead they try to combine them in an awkward way. For example, they are forcing most people who are used with the regular Windows interface to use the completely different “tile interface”, which also has very little app compatibility. You basically have to go back to the regular mode for all the old apps. So then what’s the point of combining them? In the same time, it keeps all the bloat underneath for people who actually want just the tile-Windows, and are more forward-looking than most users.
Microsoft will make the mistake of pushing Windows 8 tablets with x86 hardware first, which will also prove to be a disappointment from a battery life point of view, and it won’t be until the end of 2012 or the beginning of 2013 when the ARM-powered tablets will be ready. The low prices and proliferation of Android tablets should give Android a strong foothold in the tablet market before Microsoft even gets a chance to get its tablet strategy together.