If they are planning an expansion pack / sequel, they only have less than 2 months to churn it out as I doubt Lucas would want anymore pre Episode III material released after the film.
Here's hoping though. Republic Commando is too high in quality to just fade away. Even moreso, seeing it mae such a lasting impression. Im definately not one for any form of Imperial Commando, because there would be less genuine 'good' in the game. No matter what kinds of ideals you and your squad mates had, im sure any or all orders you would receive would have evil conotations of some sort seeing as Palpy is calling all the shots in the timeframe we're all most familiar with.
So its quite the conundrum im afraid..