Inquisitor was supposed to be a class in Vanguard Saga of Heroes but was ultimately shelved. I can't remember the exact details on why, but I'm pretty sure this is what Visionary Realms is hinting at.
Taken from http://www.tentonhammer.com/guides/inquisitor
"The Inquisitor is one of the many new classes to be released in Vanguard: Saga of Heroes. Much about this class is still shrouded in mystery. All we know at the moment is mostly speculation from what little information we have been given. The only solid fact we know is they are Protective Fighters.
It is speculated that this great new tanking class will have the unique ability of possibly countering spells from a caster. It is possible as well this class may make use of Psionic powers or some other arcane form of magic. There has been no real solid official information as of yet on this class."
Yesterday, Kilsin said that this Secret Class subforum is obsolete - there are no other classes that have a chance of being on launch day other than the ones they showed in the race/class combo chart. This subforum won't be transferred over to the new forum website. Which is somewhat sad. I was kinda looking forward to a big reveal. Now, that's not to say there isn't a chance an Inquisitor-like class will come with some expansion in the future. But that's not where their focus is at all right now, so they're not "hinting" at anything. They're currently just working on getting the classes on the chart ready for launch. We'd be lucky if we get Bard and Necro at launch, let alone soon after.