I'm not sure, but its pretty certain that not all Presidents attended Arlington every year. I am reading he will be attending a Chicago area Memorial instead on Monday. Calmer heads should prevail here on FR. Some are still posting the “He'll be with Paul McCartney” rumor even though that is being debunked. That being said - We are at War, and I thing any President during a time of war should out of respect for those dying on the battlefield attend Arlington. Be it Bush or Obama.
See post 25 (posted by silverleaf) about attendance of Memorial Day ceremonies at Arlington by previous presidents.
Thanks, silverleaf for the information.