The Specialist class abilities centre mainly around support, by keeping the enemy's tech down or by giving your squad mates an extra shot at the target by deflecting oncoming enemy fire. The portable EMP generator, codenamed "Blackout", can disrupt enemy technology for a short time and also serves as a flashbang grenade, temporarily blinding any nearby opponents. The A.E.G.I.S. creates an energy field around the Specialist allowing them, and any squad mates within, slight protection from direct fire.
That A.E.G.I.S. gear sounds a little far fetched to me, but considering that one of the other featured classes has active camouflage I guess it isn't too out there. For players interested in giving the beta a shot, they can still sign up via the Ghost Recon Online website.