This information was relayed by the Nokia Inc. President Chris Weber in an interview with AllThingsD. According to him, Nokia will be out of the Symbian and S50 business in the North America when they launch their Window Phone 7 devices. Their focus will then be just on the new phones and their accessories. Nokia knows that this may be their last chance at a comeback and if that fails anything else wont work either, as has already been proven by the mediocre success of Nokias other platforms in the North America.
As for the Windows Phone 7 devices, Weber mentioned that Nokia is putting a lot of effort and investment into them and the phones are being developed in and for the North America and will be sold globally. We hope for their sake that their efforts arent in vain.
source: GSM Arena