One of the good things about Adobe's product line is that they "work together". Same tasks require the same interface. Shortcuts are consistent.
On the free desktop we have two major graphics applications, Inkscape (http://www.inkscape.org) and GIMP (http://www.gimp.org). It will not be uncommon to have users needing both apps in their workflow. I hope you guys agree trying to have similar consistency helps to provide a sane user experience.
To be specific, there are areas where GIMP & Inkscape provide similar functionality in a slightly different way. For now I will ignore the path tool. An inconsistency that came up while I was working on something is the mouse wheel behavior. GIMP uses shift+scroll wheel to zoom, Inkscape Ctrl+mousewheel. GIMP uses Alt+mousewheel to pan horizontally, Inkscape uses Shift+mousewheel. I've filed this as http://sourceforge.net/tracker/index.php?func=detail&aid=1115612&gro...
Another area is the aspect ratio constraint and other transform modifiers.
Note that this isn't a user-transition problem. People like me will be using GIMP & Inkscape simultaneously. It's _not_ about forgetting what a user has been used to in the past. Having inconsistent behavior makes one stumble in both apps.
It would be cool if somebody found the motivation to write up some extension to the Gnome HIG, defining a standard behaviour for gfx apps (*hint* *hint* ;).
Sorry for cross posting, but I hope to initiate some discussion among both camps.
cheers