Australia / Polish Military (Polish and Australian citizenship) [3]

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.