The following packages from GNOME 2.1.2 are in sid and need to
be regressed or removed from sid.
ORBit2 2.5.0
acme 1.99.9 (doesn't exist in 2.0.2 so should be removed)
bonobo-activation 2.1.0
eog 1.1.x (gnome 2.0.2 has 1.0.3)
gnome-games 2.1.0
gnome-media 2.1.0
gnome-terminal 2.1.0
libbonobo 2.1.0
libbonoboui 2.1.0
libgtkhtml 2.1.2
So it looks like there is a tad of building to be done.
Jack