This is in fact a bug in apt as well. A fresh install of 64-bit raring will try to pull in gnome-exe-thumbnailer:i386, which in turn will ask for icoutils:i386, which will then conflict:
libunity-webapps0 : Depends: unity-webapps-service but it is not going to be installed
Rather than give up and declare it hopeless here, apt should instead just not try to install the merely recommended package gnome-exe-thumbnailer:i386.
This is in fact a bug in apt as well. A fresh install of 64-bit raring will try to pull in gnome-exe- thumbnailer: i386, which in turn will ask for icoutils:i386, which will then conflict: service but it is not going to be installed
libunity-webapps0 : Depends: unity-webapps-
Rather than give up and declare it hopeless here, apt should instead just not try to install the merely recommended package gnome-exe- thumbnailer: i386.