What I'd most like is realistic classes & vehicles. Imperial Army troops as the main Imperial trooper, for example, and stormtroopers as a assault/specops/marines type. No dark troopers, cool though they may be. No things like Actis interceptors for ordinary pilots-- we have Nimbus fighters, V-19s, and so on for clones now, so there's no need to shoehorn anything in. No having all rebels wear the uniform of the freaking Alderaanian marines. Uniforms that change depending on the environment; winter camo, urban camo, etc. Officers would be good; I'd rather they be able to call down orbital strikes than scouts. More unit variety; the CIS should also have various mercenary types fighting for them, and the Empire as mentioned above should sure as hell not be all stormtroopers. No battles in places where they don't make sense-- Dagobah, for one, and Polis Massa. More EU content. Less focus on recreating movie battles.
And no damn Jedi as playable characters. We have plenty of games featuring them. And if they must be included, use them where they make sense, i.e., only on the side of the Republic. CIS Dark Jedi were few and far between, the Emperor's Dark Jedi/Sith Adepts didn't serve with the armed forces in general, and the Rebels didn't have any Jedi until much later, and even then, few served with the military.