Will they be a thing? I do love me some wraithguard.

There will definitely be Wraithguards. I'm surprised that you don't know it man, considering that the Wraithguards is on official Eldar artwork for EC.

Artwork doesnt mean in game but it was announced Wraithguard will be in it. Personally I want Wraithblades too.

They will be in the game in some form, according to the devs, and they will have something to do with the character progression of Warlocks.
Personally, I do hope they'll be in it, and I think they're going to be the TEQ of the Eldar faction at launch.

I'm not planning on playing Eldar but I would love to see Wraithguards on the battlefield.

I'm not planning on playing Wraithguard, but I'd like to have them by my side in battle.

One would presume that Warlocks would be able to further specialise into Spirit Seers. If so, they could have a Wraithguard following them around. Or they would be an Elite class, akin to terminators or such.

As long as they're not a seperate class and we don't start seeing dozens of Wraithguard running around everywhere on their lonesome.

I thought the way Wraiths worked was as you level up you choose to become the Wraithguard?

Nope.

This, as EnginseerMidas says they are our TEQ (terminator equivalent).

The class system is similar to BF or PS2, you choose a class every time you die, maybe we can even swap classes while you are alive in some facilities still don't know about it.

I know I'm a bit late and I'm probably dreaming, but I would like to play the Wraithlords. How awesome it would be to march to battle with these giants by your side!