The Blackberry Aristo has, until now been referred to as A10 model number, but according to one forum member over at Crackberry, this could be nothing more than a codename.
According to this report in pre-release BlackBerry 10.2 code the A10 has been referred to as the Z30. There is no definite confirmation on this model number, but many believe that this will be the final name considering the Z10. Common perception is that there will be the Z10 and the Z30 with room between the two models for middle of the road models to come.
Stay tuned for more news on the Blackberry Z30!