There is a reason why TCL signed up with BB, and why both are partners in phone.

BB devices actually sell very well thank you very much. They are high priced and catered to the pros. Volume is of course much lower then the top-tiered but its profit that matter more. They don't need to sell an insane volume in order to make money. 

BB are immensely popular in Asia Pacific and parts of Europe. Pretty OK in Canada but a drop in the barrel in America. The big growth market is China and TCL will make sure of that. 

BB phones is strictly a premium brand with unique features in design, keyboard and security. The only question remains is what will they do with BB10.