Gruber and Marco are tactical in their praise of non-MS products. They'll praise something they think has no chance of threatening Apple. Despite Android's flaws, there's also tons of stuff in it worth praising, but you'll rarely (if ever) hear them say a peep about Android.
Likewise, Surface is a LOT more threatening than Windows Phone. They don't view it as a cute toy, but rather a serious threat to the iPad.
Don't you find it the least bit odd that Marco does a story about his experience at the MS store, with pictures of an empty store and never references any of the stories that talked about full stores?
If Marco and Gruber actually like a new Windows device it likely means they don't think it will sell much. If they think it has potential, they'll find a way to bash it.