Returning vaguely to the topic...

From the Black Library "March of the Titans" offerings, I'd say that we might even get the "mythic" Psi-Titans this time around (though unlikely in the first run of the rules - I suspect they'll save that for a supplement if the basic game does well).

They published a few short stories that had them.

D'awww, did my smiley hurt poor Splash's feelings? It was a playful, harmless joke. You might want to grab a cookie, I think your blood sugar's getting low and you're getting cranky for it.

AOS != Adeptus Titanicus

Let's keep this thread on the tracks

There are rules for Psi-Titans in the latest FW Horus Heresy book as they fought on Prospero against the Thousand Suns. You can google up the background and rules easily enough and I'd expect a FW psi-titan later this year - modelwise it's just going to be a variant weapon arm for the warlord.

I would think these would involve more than just a simple arm swap.

I'd guess that much like psyker figures for the game, there will be a head and "cowl" change as well.

Given the complexity of the Warlord kit, they could make quite a few changes by swapping out specific parts virtually anywhere.

Well in the Inferno book it's just a standard warlord with a variant left arm mounted weapon designated Sinistramanus Tenebrae (left hand of darkness) psychic weapon. Acts like a vortex missile in effect anything hit by the beam is torn to pieces and scattered to the beyond, other targets in close proximity are simply struck dead with out a mark on there bodies as if their souls have been sheared from the bodies.

They're now called the Ordo Sinister, which is disappointing as it ignores and re-writes the old background from Titan Legions for the Ordo Sinister (back then they were a titan legion composed just of 12 Emperor class titans with no connection to psi-titans) which I rather liked.