Windows Media Center is not preinstalled in Windows 8 Release Preview. If you want to use Windows Media Center, you need to add it by following these steps:

Swipe in from the right edge of the screen, and then tap Search.
(If you're using a mouse, point to the upper-right corner of the screen, and then click Search.)

Enter add features in the search box, and then tap or click Add features to Windows 8.

Tap or click I already have a product key.

Enter this product key: MBFBV-W3DP2-2MVKN-PJCQD-KKTF7 and then click Next.

Select the checkbox to accept the license terms and then click Add features.

Your PC will restart and Windows Media Center will now be on your PC and the tile will be pinned to the Start screen

This is awesome. Media Center should be included with windows 8 anyways! But oh well. How did you figure this out??

Any changes to the media center or same old?

This you can find on Microsoft site, but will take you more than 10-15 minutes, so I just want to make things simple

i wonder if we can install using that key... i should try it out

Maybe the key was legal and there to test the media center? Who knows. But really WHO NEEDS to pay for media center as an add on, when theres several BETTER media centers like XBMC?

You can also find that key and information in the Windows 8 Release Preview: Frequently asked questions.

Seems I don't work when you enter the key directly during the setup, due no (correct) image available.

Windows Media Center is available only in english language?

Not only in English. Others are also available.

But it keep language from OS or it's possibile to select other languages directly from the application?

Ever tried to watch TV in XBMC?

I found out about the codes by Google, nice of Microsoft to allow us to test that also, although I didn't see any changes from the one that came with 7, which was probably the same as one with Vista.