The price they launched at was aimed to give room for 3rd parties to make their own WinRT tablets and sell them for less than the Surface. OEMs never really made a go at it (understandably) so I think now Microsoft can decide to be competitive with the price but I still think that means more than $300 since the Surface is a premium device.
The Haswell processor may make them more irrelevant but it's possible they could aim for low end now with WinRT. Any Windows tablet sale is overall a good thing for the Microsoft app store. Almost all Metro apps work on Win8 and WinRT so it's possible that an RT device actually makes more sense in the future than it does right now if the app store continues to grow.
The Surface Pro is a premium device, the Surface RT is a budget device at a premium price.
If Microsoft had launched the Surface RT with a Snapdragon S4 Pro and 1080p screen its would have had a chance at being competitive.