"When you first build a Frigate Facility, you get access to Torpedo Frigates. An Advanced Research Facility then gets you the Ion Cannon and the Flak - but there are individual research items to unlock Marine, Defense and Cloaking Frigates. Much the same is the case with the Vaygr Fighters - making the choice of exactly which specialized ships in a certain category to construct much more relevant. The gameplay impact of specializing in Marine Frigates (for capture) over Cloaking is huge - as is the difference between someone who specializes in one subset rather than another player who's going for a diverse and flexible force." - Morgan Jaffit, Designer

Morgan later said that he had made an error mentioning a "Cloaking Frigate", but in the ships directory of the released HW2 .big file, there is an entry for "hgn_cloakingfrigate", so it appears that there was at one time such a ship. Unfortunately, as with the other outtakes, there is an entry for the ship, but no stats or models. 

There are no confirmed images of this ship as yet.