It's taken a long while, but here we have it at last.
Jacob Taylor at 0:46, appearance unchanged.
Miranda --oh so very briefly-- at 1:04, appearance unchanged.
Samara at 1:11, appearance also unchanged.
And Legion, too, don't think I missed him.
Also, the Orbital Bombardment Designator has made another appearance.
Aside from the whole "female Shepard" thing, this trailer is really showcasing the increased cinematic quality in ME3. Like the Uncharted games, to name an example.