Microsoft Mobile : a new era of Nokia or a new brand name
Personally i think MS will probably ditch the Nokia brand for a new name. If you think about it - that's probably the best long term option. They want to be the "One Microsoft" and for an average consumer Nokia will always be Nokia and not part of the Microsoft.
I hope MS thought clearly about this. Their new motto is "mobile first - cloud first" and that should be a clear sign they want to invest more in mobile technologies. If they want to create a new brand they will have to invest billions of dollars in marketing. Nokia is not a strong brand in the US, but in the rest of the World it's known by many consumers of mobile phones. I would say most WP phones are being sold because of the Nokia brand and not because of the Windows Phone. So, if they want to start from a scratch they'll need a powerful message to everyone in the world. I'm talking about Samsung kind of money for advertising.
The second option is to leave the Nokia branding. It would clearly help by not disrupting what was done until now. Nokia and Windows Phone are more and more common, especially in Europe and Latin America. That image is very fragile and if you want to scrap it first you'll have to come with something even better. I doubt that partial Nokia branding like Lumia would be as successful as the Nokia branding itself.
Whatever they decide they need to throw a decent amount money on marketing. WP needs a strong push in the back to really get a decent piece of the market share.
By the way i have a feeling that the true flagship for the 2014. (probably the 1030) was delayed until Nokia finally becomes part of the Microsoft.
I'm eager to hear your opinions. :)