Pretty much all the experimental means is that it's not in a book yet, however they have been known to tweek things from time to time before including rules in a book!
I was a little late on this, because we were out at Feast of Blades over the weekend, but here it is for all to see! So buying this -MBG
Courtsey Apocalypse 40k and Forgeworld
Rules Summary
Heavy Support Flyer with Hover mode
220 points for loyalists (All chapters, including BA, and the Tyrant's Legion list from IA9), 200 for chaos
Armour 12/12/12, 4 HP
Avenger Bolt Cannon - S6 AP3 Heavy 7
2 Independent Turret-mounted quad heavy bolters - S5 AP4 Heavy 6 Twin-Linked
4 Hellstrike missles - no profile given
Machine Spirit (Loyalist only)
extra armor
Special rules:
Deep Strike
Strafing Run
Independent Turret Fire (described below)
Relic of the Armoury (Non-HH Legion lists only)
Can take Armoured Ceramite
Chaos and Horus Heresy Legion armies can replace quad bolters with Reaper battery - S7 AP4 Heavy 4 twin-linked - 10 points
Blood Angels can replace Hellstrike Missiles with Large Blast blind/locator beacon missles for free
Non-Chaos(Marines, Wolves, Dark Angels, Blood Angels, Vangaurd assault armies and Tyrant's Legion) can replace the quad bolters with twin linked autocannons for free
As long as you're normally able to shoot, the turret weapons (quad bolters, reaper battery or autocannons depending what you take) can each fire at their own target independently, and don't count against the number of weapons the Fire Raptor is able to fire in the shooting phase(hence why having Machine spirit, and paying 20 points for it seems sort of pointless).
Chaos raptor can take daemonic possession for 20
'Relic of the Armoury' A primary detachment can have one model with that rule normally. If you wish to take a second model with 'Relic of the Armoury' in your primary detachment, the detachment must include a Master of the Forge, Interrogator-Chaplain, Recluisarch, Rune Priest with Beastslayer, or Warpsmith, specific codex dependant, obviously. This represents the rarity of the vehicle requiring the blessing of some 'keeper of relics' to oversee their use.