I'm looking at a fun project just now as I roll forward all my development notes and ideas from my old notebooks to a new consolidated notebook. I used to play a bit of the Star Wars Battlefront game and have always been interested in this universe since the first film so a wargaming adaptation was on the cards.
I will make use of the WWII rules as the core engine. I've used these for all my army level simulations so far. The tactical level will be set at the company and battalion level. For the squad level which models the game I will use my Skirmish Rules adaptation and develop its own lists based on the faction makeup of available troop types.
There are four factions to consider: The Republic, CIS, The Galactic Empire and the Rebel Alliance. It should be interesting designing rules for the various weapons systems and the unique vehicle types and fighting machine that this universe presents.
As an aside I got the Star Wars X-Wing miniatures game for Christmas which is great fun to play and provided a catalyst to me getting this wargaming project started.