the venom was added in the 2nd version of the Harlequins army list. It was not there originally. In the first iteration of the harlequin army (rt era) - they could loot other transports… YES LANDRAIDERS!.. in the compendium (which combined stuff from earlier WDs) they show this.
I remember passing by the RT rule book several times at a couple LGS back in the day, I was an RPGer, and always looked at the stuff for war hammer and RT when it came out. But it wasn't until I saw the WD with the harlequins jumping out of the cover did I decide that I must play 40k LOL… I snapped up the WD… and soon picked up the box set of the first harlequin models.
i am hoping they have some DeepStrike assault capabilities - web way portals - along with the more traditional eldar/DE stuff.
-d