I would argue no, under the scientific dictionary definition of a planet, only 2 of those would be large enough to qualify. On the other hand with the new ruling some planets are and some planets aren't planets. That is simply stupid. If you call something a "Giant planet" like Saturn or Jupiter why is it still a planet when calling something a "dwarf planet" means its not a planet. I would say that 4 giant planets + 4 Terrestrial planets + 8 Dwarf planets = 16 planets, although under the new definitions someone could probably say its 4 because Giant planets may as well be called Dwarf stars now for all we care.
Technically however, Sedna exists outside of any known asteroid belt and even at its closest isnt predicted to pass into our Kuiper belt, but it gets the dwarf planet classification because we aren't entirely unsure that there might possibly be more of them out there. Now despite being reasonably sure of its size and having a decent grasp of its composition we cant REALLY be sure if its a "Planet" or a "Dwarf Planet" we are giving it the second because at that distance there is a high likelihood that we wouldn't find other objects out there, however if someday we have the technology to travel there and DONT find anything else it would become a planet, this is a sign that its a terrible system.
I look at it this way, I drive a compact car and my one friend drives a fullsized sedan and my other friend drives a large pickup. Since my car is a "Compact" it is now technically some kind of motorcycle because it isn't fullsized? Or should it loose its car status and be a motorcycle because I commute through city traffic while they travel highways? How do you define a car anyway, we don't have a good system for that, but i bet until we do we will have a lot fewer arguments as to what constitutes a car.
