Re: Captain America Easter Eggs Thread *Spoilers*
Sorry if this has been mentioned, but the music playing after Howard Stark gives his proto-repulsor demonstration, is the same music that plays at the Stark Expo in IM2, and in the end credits, "A bright new morning is dawning. Make way for tomorrow today...etc, etc."
Also the weapons used by Hydra have the same sound effect as Iron Man's repulsors. Considering Howard finds the tesserect, that must also somehow tie to the ARC reactor.