Alan: I like how the GIMP provides a submenu for Zoom and specifies the Zoom levels as percentages, and I'd like it if Inkscape could try to follow the GIMP on this one. The whole previous/next zoom idea seems really weird to me.
I prefer how Scribus and the GIMP use only Show rather than Show/Hide and I think this is recommended by the Gnome Human Interface Guidelines.
There is certainly a lot of room to make things more consistant here.
Andreas: Another nice thing that both GIMP and Scribus make use of is checkboxes, so a user can see if a setting is active or not.