With Iraq's recent victory in the Asian Cup Final over Saudi Arabia, Iraq joins Italy (World champion), Brazil (South American champion), USA (North American champion), and South Africa (host country) as the teams currently qualified for the Confederations Cup in June 2009. The remaining three spots will go to an Oceanic team (probably Australia), an African team, and a European team. The Confederations Cup is a warm-up tournament that will make sure South Africa is ready to host the World Cup the following year.
The Confederations Cup is run like so: two groups of four in a round-robin style, followed by semi-finals and then the final. Assuming Australia qualifies for the Confederations Cup, it is likely that Iraq will play either a former (Italy) or current occupying power (USA, Australia). Iraq and the USA have a 50-50 chance of playing each other in the group stage, and if either team were to advance (likely for the USA, unlikely for Iraq) the chances naturally go up. It is further possible that England, Poland, or the Czech Republic could qualify through the European spot by winning Euro2008, further occupying countries that could meet Iraq. If the European spot is taken by a member of the Coalition of the Willing, then it is a mathematical certainty that Iraq will play a current or former Coalition member.
Violence at the game will be unlikely - I don't foresee large numbers of Iraqi hooligans traveling to South Africa to attack Americans when they can do it at home (a new iteration of the flypaper theory!). Furthermore, the presence of South Korean troops on Iraqi soil didn't seem to be raised as an issue during Iraq's semifinal against South Korea. However, given the "special relationship" between Iraq and the USA, if any American troops are still in Iraq in June of 2009, I'd advise them to stay indoors.
The US team is much better than Iraq's team, especially if many of Iraq's players use the opportunity of their success to get contracts playing abroad and leave Iraq permanently (adding to the diaspora), or are assassinated. However, in the event of a Iraq vs. USA, Iraq vs. Australia, or Iraq vs. England, Iraq will be singularly motivated. This far out, I will refrain from offering a prediction on the match itself.