From the Inkscape Wiki:
http://inkscape.org/cgi-bin/wiki.pl?IllustratorUsers
Zooming : Plus and Minus Keys
Instead of holding down the Ctrl key and pressing + or - to zoom the canvas, in Inkscape the artist simply presses the + or - key to zoom.
Can Ctrl++ and Ctrl+- be made to work also?
This would be benefit to Gnome users too, the Gnome HIG currently recommends
Zoom out Ctrl+ - Zoom in Ctrl+ + but Ctrl + = should also work so that users with +/= on the same key dont need to think about it
and Zoom Normal aka 100% is Ctrl+0 because it is conveneintly beside - and + (and it is what Mozilla uses)
To be as clear as possible I'm suggesting additional keybindings for these very fundamental tools rather than replacing or getting rid of any bindings.
Sincerely
Alan Horkan
PS Did a quick search of the Feature requests but didn't see anything that seemed relevant.