I don't think a UI will help. The market response to a partnership with MSFT seems pretty apparent - and it isnt' good.
The again, where I see a Short, other's see a Buy Opportunity. Me, I wouldn't want anything to do with it. MSFT has earned ill-will; people rush out to buy Android, iOS or RIM phones... people hold their nose and buy MSFT products because they have to. In the mobile market, they don't 'have to' buy MSFT.
Nokia has the international market’s attention and has had for 15 years. I see them as going forward with Win7 embedded but applying their own graphical and application standards. Most people haven’t a clue who Microsoft is or isn’t and just want a good device that wows them.