Elop today mentioned today on Nokia’s Press Conference, that Nokia brand on their phones will stay for now, but that could change in the future. Though feature phones will keep carrying Nokia brand. Nokia itself wont be able to use Nokia brand on its devices before 2016.
Maybe not all that surprising as the Nokia company is still out there and the branding is set to get complicated on customers. Microsoft acquired Lumia branding, so that’s one option. Microsoft also likes to attach Xbox to everything, so maybe in 2 years time we will get Xbox 1850.