Otherwise, look to the history of your company. How have your boss and other managers handled employees' resignations? If you see a pattern of upper management refusing to let the team members work out their notice, you can likely expect the same.
Also think about your relationship with your manager. Would he or she have reason to think that you'll waste your last two weeks or distract your co_workers instead of doing what you can to make the transition seamless? If so, you may be asked to cut your two weeks short.