yes it would be similiar to 3D view only ortho and constrained to a vertical axis. actually a comprimise could be to stay in the current view when 3D view icon is selected; ie if you are in front view and you click 3D view icon the screen wouldn't change but you would be free to RMB rotate and the arrow keys could be used to constrain rotation either left/right or up/down. or instead of clicking 3D icon just link the RMB to break out of front/top... view automatically.