Well, the boys at Film School Rejects have cleared things up for me based on their report that Captain America can be seen in the Alternate Opening found on the second disc on The Incredible Hulk Special Edition DVD (10.21). They sent over the link and I gave the pic a peek and had no idea what I was looking for or at, but Cole sent over an explanation:
I underlined the one thing I didn’t realize I should look for, Captain America is under the ice, and wouldn’t yah know it… there he is. I have taken eleven screen captures of the sequence and so as not to put any arrows or anything on the pics just look in the lower left hand corner and you will initially notice a red, white and dark blue circle. I have done a little color work on the pic to adjust the contrast and saturation a bit to make it stand out a little more, but by the end you should see a faint body under the ice and the shield can be seen clear as day.
Kudos to FSR for the find and thanks to Cole for clearing things up for me.
Captain America is expected to have his own feature film on May 6, 2011 called The First Avenger: Captain America. Details are scare, but we do have what is said to be an official synopsis up right over here.