Microsoft made big headlines last September when they announced that Windows 8 would support the ARM processor on Windows 8 tablets. At the time of the announcement it was assumed this also meant existing applications which in itself would be quite an amazing feat.

Windows Weekly co-host Paul Thurrott had a bit of breaking news on this week’s podcast which is part of the  TWiT Network.  He said he recently learned from his trusted sources that ARM tablets with Windows 8 will only support Metro Style Apps. Chief among the omission would be the desktop app that supports existing x86 applications. Mary-Jo Foley was also on this week’s podcast and her thoughts are:

I don’t hate the idea that Microsoft might pull the plug on the Desktop App on Windows 8 ARM tablets. In fact, I think it’s the right thing to do if Microsoft and its partners want to position ARM-based Windows tablets as more of a true iPad competitor.

Existing Windows 7 tablets like the HP Slate tend to not be as energy efficient for several reasons like requiring fans for cooling. The reason for this is the HP Slate is a full desktop PC only dressed as a tablet. The big news about ARM processor tablets running Windows 8 is they should offer amazing energy efficiency because the ARM architecture is designed for low powered devices and as Mary-Jo said, “a true iPad competitor”.

As the ecosystem that traditionally Windows has offered, it is fully expected there will be non-ARM based tablets that will offer the full desktop experience as well as traditional desktop/laptop PC’s, but all working within the same operating system called Windows 8.