Not too sure about the re-done Borg Cube explosion at the end of the trailer. Looks like they freeze-framed/slow-framed the explosion, then when the enterprise zooms off let it play. Original somehow looks better. Hope it's just an unfinished shot but I kinda get the feeling it's the finished version.
Someone helpfully posted a comparison video with the original version:
http://www.youtube.com/watch?v=lpvQ46v13Lw