Looks like Windows 8 has the same features as Windows 7 Home Premium.
Some confusion, but I think Windows 8 will include Windows Media Center, but WMC will be available in Windows 8 Pro only as an optional cost add-on.
Windows RT name seems to add more confusion. It apparently will not be sold at retail, so that may not matter much.
I don't yet see any reason to go with it, but I might if it's available at a heavy discount, like Windows 7 Home Premium was available for $50.