It would be like other long visas, you go immigration with old and new passport. Why wouldnt it be? If you worry, you have a reason why you think that way?
really? I see you havent heard of it since submit documents? Sometimes after it shows pending approval, you can ask for them to finnish them in hurry, if youre lucky :) i got mine in 2hours after telling then my flight is in 2days and still pending approval