Dark Forces Mod wouldn't work in Empires At War. You could try, but it would be messy and not as fun.
Star Wars: Galactic Battlegrounds kinda sucked, because it was basically an Age Of Empires II mod using Star Wars characters, etc. Empire At War is good and is how a Star Wars RTS should've been in the first place, especially being a unique designed game.
I'd rather they bring on the next in the Dark Forces/Jedi Knight series though
If they come out every 5 years, then I say bring on 2007/2008! They could do some nice force powers and general gameplay and graphics with todays technology. I'd like to see more puzzles with a greater variety, most of them so far just require your lightsaber, I'd like to see mind tricks and other methods to help you advance.