They mention Jar Kai...But no rules for it. Yet. But I suspect when we start getting splat books we will see a couple more lightsaber forms. like the Seeker or Sentinel career I suspect will get Jar Kai. Maybe warrior will Vapaad. What else we missing?
There's also Trakata (which is really more of a technique than a Form), which revolves around making use of the lightsaber's blade being able to be switched on and off. There's also Sokan, which is really more of a mindset than a true Form, and revolves around making full use of the environment to gain the advantiage in a fight.
As for Vaapad, that's more of an off-shoot of Juyo that Mace Windu developed and really didn't share with anyone outside of a couple of Jedi Masters, so any potential LS Form spec that's based off of Form VII will likely use Juyo in the name.
Lastly, there's Trispzest, which is an arial-based lightsaber combat style, and is really freaking uncommon, having shown up in the old Marvel Comics and an opponent in one of the Jedi Knight games. This one I doubt will get a full spec.