Hmm, I missed this, but in the scene where Tony is getting out of his armour and has the great line (this is not the worst thing you have caught me doing) Captain Americas Shield is on his work desk (Middle-lower left corner):
I am loving that they are tying in other movies in subtle ways, if you haven't heard they are already planning the next 4 years:
In order to focus its attention on maximizing the success of an Iron Man sequel and the launch of Thor in the summer of 2010 and because Marvel believes that the summer is the optimal time to launch a new property, the Company will not release a self produced film in 2009. Marvel plans to launch its 2010 film slate with the release of the sequel, Iron Man 2, on April 30, 2010, followed by the launch of Thor on June 4, 2010. Additionally, Marvel is planting its feature film stakes for summer 2011 with an Avengers-themed summer - a two-picture project which will debut on May 6, 2011 with The First Avenger: Captain America (working title), followed by The Avengers in July 2011.