Hi All,
more speculation on the 'attack' on Dol Guldur here (and links within)-
http://forum.barrowdowns.com/showthread.php?t=1511
From the texts I don't think there's enough evidence to say one way or the other whether a physical attack happened. However, I'm inclined to think that there were Elven troops deployed, together with Saruman's devices and some sort of 'magical' backup from the Wise.