The source of the leak indicated that the QWERTY N-Series BlackBerry device may be called the X10, but could not confirm. While we wait for BlackBerry 10 to be unveiled next month, what do you think of the new naming scheme? It was probably inevitable, given that the four-digit plan was running out of room to grow, 9900, 9930, and so on. We were also pretty certain that a five-digit naming plan would not be very appealing.
source: Unwired View