Drudge may not know what he is talking about, but neither do you. In order to go to Iraq, one must:
Join the Army - done
Get a commission - done
complete your requisite officer course - ongoing
join your Regiment - will do soon
Regiment gets posted to Iraq - Expected, but hasn't yet happened
Accompany Regiment to Iraq - On approval of MoD (Uncertain)
So, he is on track to go - but remains to be seen.
Yes, he went through Sandhurst ( a quicky training course, as opposed to an actual, full fledged course ), was automatically part of the army upon graduation, and is a commissioned officer. But this bit of "news" has been floated at least two times previously. It is just a rumor, that keeps on being repeated, based on the fact that it is claimed that Harry once said that he wants to go to Iraq.