Im an Australian and have just applied for Polish dual citizenship because my grandfather is polish. What will my obligations be towards the polish military if I succeed with polish citizenship? Im told that as of 01/01/09 that it will be optional, is this true? Also is there a chance i could be called upon at a later date for military service? I dont plan on living in Poland permanently.
I don't think you should worry about it. They will leave you alone. By the way... please note that if you write Polish the first letter should be a capital letter in similar way you write Australian ;-)
Most likely you will be required to get a "ksiazeczka wojskowa" (military booklet) which shows your official status, you need this booklet by law and it is often asked for when registering at a place of residence. It involves beuracracy and some time to get, also you get a physical exam and then the "comission" and the army doctor give you a stamp in the booklet which shows your status: A for fit for duty, B fit for duty in time of war only, etc...
Now that Poland is going for volunteer only force, you have no obligation to join (same if you are over a certain age, I think 30 or something close to that). They can not penalize you for not signing up in past years because it is obvious you were living permanently overseas, either.
As for the "booklet" of course you do not even need to worry about this crap if you will continue to live outside Poland on a permanent basis.