A Captain America film has to cover both his origin in World War II and his re-emergence in the modern era; there are two ways to do that: linear and non-linear. From whats been said, it seems theyll be doing a linear approach, but I think it would be better to do a non-linear story: my idea would open with the plane crash and Cap being frozen, which he wakes up from (as a nightmare); hes been in the present for a little bit, and we get further flashbacks that go into his origin in the war, cued to various developments in the present (going to the White House in the present recalls him meeting FDR, for example; theres a really awesome scene from the mid-90s "Sentinel of Liberty" Id love to see adapted). In the present, the story would be Rogers increasing conviction that his World War II nemesis, the Red Skull, is still alive, and behind a series of terrorist attacks occurring around the world. SHIELD would have a fairly large role in this, since theyre usually a key part of Caps series, and major supporting plays like Sharon Carter and Nick Fury work for it (probably Sam/Falcon too; Im not sure if hed be a superhero in this version, or just a SHIELD agent).