^^^I'd have to agree there, CIS and Republic are the next best to the original Rebels and Imperials.

I myself would love to see a Pirate faction, using blackmarket technology. Perhaps make a map such as this:

Imperial Forces have decided to crack down on illegal arms smuggling in this sectory, and have traced the shipments down to a pirate base in the ? Sector. A small imperial group has been dispatched to eradicate them.

Meanwhile, the Pirates have been alerted to the Imperial attack, and must do whatever neccesary to stave off the Imperials so that they can move their operations elsewhere.

The battle could either be a fleet battle, or a battle on a spacestation, where the Pirates have ships like Cloakshapes, Preybirds, ugly's, Y-wings, Z-95's, etc.

Likewise, the Empire could be outfitted with a small strike group of whatever ships First Strike decides to give the Imperials, and troopers armed for boarding operations to go against the pirates.

Edit: Pirates could also find themselves amongst Rebel forces, as a supplementary force.