My group wiped 3 times on this encounter, it indeed is very tough.
Our group was
26 corruption sorcerer healing (me)
22 Powertech dps
24 Jugg tank
25 sniper
Essentially I couldn't keep up on the healing and I would eventually run out of focus and we would wipe. The strategy that we had the most success with was burning down the boss without aggro, then getting the other 3 low in health, then killing them. However, we wiped the last time with the final two at 10% health. We probably could have gotten it eventually but the dead guys didnt respawn for the 4th attempt and we killed him.
This boss is MUCH MUCH tougher than the other bosses and should probably be brought in line with the other instances. It was clearly overly buffed from beta.