Yeah...except EVERYONE can get it really easily, as all you need is WiFi, and it was available by launch. So, it's not as secret as those four. You might know the Pokemon I'm talking about though, since it was seen a lot in pre-release material. I expect we'll probably get its English name soon before the games come out.
Also, with the Japanese version, there was also a WiFi event offered up when the game came out allowing you to obtain a 100-stat little Legendary by the 3rd Gym who is part Fire, so there's another one. I assume the English version will have it as well.