Is there a market for a 5-7" RT Gaming device

The 3DS and Vita aren't doing as well as their respective manufacturers expected. Meanwhile, the iPod Touch and even Galaxy Player are selling like hotcakes, which suggests that people want a more convergent device for their mobile gaming.

So, I'm wondering, is there room in the market for an 'Xbox handheld' of sorts. A 5-7" WinRT-powered device with decent internals, and physical controls built in to the device, that sells for $200-$300 (to compete with all of the above mentioned devices)

So, on a technical level, this device is very possible. We know RT support mouse, keyboard and even an Xbox 360 controller. It has DirectX compatibility, apparently, so there's that as well, to encourage developers.

Throw in support for XBox Live, a few premium, XBLA-quality game titles (or maybe even allow a developer to publish the same app on both simultaneously), perhaps removable physical controls, and 'd be very tempted.

Thoughts?

Edit: Called It! http://www.theverge.com/2012/11/6/3608432/xbox-surface-xbox-tablet-7-inch