Normally, it’s not that easy to compare a comic book movie to the source material as they’re often based simply on the characters themselves rather than an actual story arc. The difference here is that Captain America: The Winter Soldier is based on a run of the same name, and it’s clear that they share several elements.
However, it does appear as if they’ve added something new as the Bucky in the trailer seemingly has super strength and is even faster than Steve Rogers! Clearly that metal arm isn’t the only enhancement he gets. The comic book version of the character is just a regular human, making it all the more challenging for him when he becomes Captain America for a time. How the movie handles all of this should prove to be very interesting!