Well this is what I got on Wookieepedia:
As of now there is no real information concerning whether the GenoHaradan survived through the later years of the Republic, the Galactic Empire, or beyond, but for centuries there has been no indication of their survival past the Old Republic era. Of course, if they had continued to thrive, then there would not be any indication of their survival regardless.
However, it can be noted that the Tac-Spec Corporation, a droid manufacturer that operated into the last few centuries of the Old Republic, is claimed to have originated as a GenoHaradan front-company. Their exclusive automata for the Republic's aristocracy, such as the FIII Footman Droid, would have been ideal agents for the organization's policy of subtly influencing Galactic politics.
Now one thing to note is that Revan's interaction with the GenoHaradan is "DS", and since the official canon for Revan is "LS" then he never killed Hulas and all those other overseers. Therefore, that reduction in membership is non-canon, so it probably should not be taken into account regarding future survival. Plus, this group survived for millennia already, so the likelihood of them dying before TOR is unlikely.
As of 3/14/10, TSL is restored. The Sith Lords Restored Content Modification by Stoney and Zbyl has been finished and can be downloaded here