Surface Phone, a good thing or not?

We have all seen (well, most of us) the truly wonderful mock-up of the Surface phone by jonas-daehnert, which is basically a Surface tablet minimized which to me makes total sense and would relate the whole line-up. Microsoft_surface_phone_8_by_yronimus-d54trfa_medium

via th00.deviantart.net

But the question is what effect would it have on Windows Phone? 1.Would it sell=most probably 2.Would it be sufficient to add enough market share, when I say market share would it be a rival to the S3-S4, iphone5 in the amount that they create as flagships. 3.Would it effect Nokia(maybe HTC) positively making people notice windows phone or would it cut sales of there Nokia 920= I don't believe it would, Nokia own about 70% to 80% of the Windows Phone pie and all the Surface phone would do is make the pie larger, I think that they could always do a Nexus style deal and allow someone else to produce it, maybe someone totally new, such as Sony who has always been thinking about entering the WP market, this would enter them strongly and as the great mock-up shows looks like it could relate to their design language more than Nokias (with the bright colours and soft edges). Sony would be a great balance to Nokia with what I believe are a premium quality OEM (think xperiaZ and xperiaT), it would get rid of the same fears that Google has with Samsung's dominance over Android that Microsoft would have in the future Someone also posted about a boring 2013 for WindowsPhone, even though Nokia will probably release the EOS and the Catwalk, and hopefully HTC will carry on to show their small support for windows phone there wont be anything new, from 900 to 920 there were obvious improvements but to the untrained I not a lot (looks, not OS)so a Surface phone would keep interests high (or at whatever level they are now) through to the Blue update. Tell me what you think?