I would like to see some new type combinations. An alternate evolution of Meditite, purely for example, into a Fighting/Ghost (derived from the fact that Meditite starves itself, it may subsequently waste away) would be rather interesting. Maybe not that specific evolution, but it's an idea.
I would also like to see some non-legendary Electric types that can stand on their own two feet. Luxray was a refreshing addition, if not for its shallow move pool, and Magnezone is just incredible, but the number of mediocre Electric types is too abundant. They need to abandon the cute electric rodent that they've repeated to no end and go for something a bit more suitably fearsome. We need more Electivires.
Finally, I would like nothing more than to see a Fire/Dragon typing, mainly because it's incredibly obvious, but also because it would add another Dragon typing without and Ice weakness. A Levitating Fire/Dragon would still suffer from Rock and Dragon attacks, but would lose the Ice weakness and the Ground weakness. It'd make people think harder about countering Dragon types.