The T-Series Tactical Droid is exclusive to set 7868, Mace Windu's Jedi Starfighter. This is a new figure for the LEGO Star Wars universe.
Minifigure Parts and Accessories
The Tactical Droid is comprised of four parts: two arms, legs, and a combination torso/head.
The head piece and torso are all one molded part with attachments for the arms and legs.
The arms are a dark bluish gray version of part 30377. It is believed that the left arm in the picture above is not attached correctly (it is upside down).
The legs are also dark bluish gray and are often seen on Super Battle Droids (part x281).
The legs are also dark bluish gray and are often seen on Super Battle Droids (part x281).
Comparing the figure to the reference photo on the right would suggest that LEGO captured many of the details of the torso quite well. The arms and legs are not quite the same, but expected for the sake of economy.
Army Building Potential
The ABP for this figure is moderate. Tactical Droids add variety to your separatist armies, but were not as numerous as other droids.
Big Draw
As the selection of droid parts expands, the new parts from this figure could be desired for potential mixing and matching. Also given that this is the first time these types of droids have been available, collectors will likely seek this out.
(Pictures via KimT's Flickr stream and Wookiepedia)