The initial list I have compiled simply by searching, but I know it is not accurate (because it's about who has posted). The search criteria was "last post after 2011-12-12" and sorted by join date ascending.
I know that Parth should be on this list somewhere... there are probably others.
These were the top 15 hits. Everyone is from April, May, or early June: Jamie, Banned, Flamin, Fac3bon3s, Kingslaya, Dubtogi, LightningLord67, RedRyder, MysticalDream, Cascade, Barbamitsos, FluffNStuff, Darkfader, and vulgarstrike. I think they are mostly founders. Are there any other founders still playing?
added:apocolypse, sun, Kingrichie, MoarPewPew, Carth, adidaman, Beanmachine, Swimmingstar (technically), Apollo (technically), maneatingtree (technically)
I'm not a founder (June 12 joiner), so I put myself as the cutoff.