+1 Trim would be nice, or just give Clip some options: Clip the top-left pixel color, or all transparency (including hidden content).
My workaround, for now, is to select & copy what I want to trim, then File > New from Clipboard
Mods: Clipping transparency, even if there are hidden contents, would be really nice in my workflow. It's destructive, but I bet loads of people use it for the same reason as me. I Trim temporarily for exporting individual layers for games, and then undo. I even have a macro in PS for hiding all, unhiding the selected layer, and trimming. I do this by hiding all the layers I don't want, and then Trim.
