As MS How would You use Lumia, Surface and Xbox brands?

Would you make Surface the 'stylish' tablet/laptop brand, and Lumia the 'colorful' branding?

Would you make Lumia for phones and laptops only, and have Suface be the hybrid laptop/tablets?

Would you create the much rumored 'Surface Phone'?

Or how about that old 'Xbox Surface' rumor for XBLA only gaming?