The lines between those have been blurring for ages, and they'll only get more obscure as time goes on. Technology is always trending towards portability, so I wouldn't be surprised to see Nintendo having some hybrid competition in the not too distant future.
Really though, I think it's silly for us to worry so much about defining it. The games are very much more akin to console games than handheld games, but it can be played as a handheld and so has weaker hardware than its competitors. Call it whatever you like.







