I don't see any issue with letting glade2 and glade3 coexist for
while. And I don't expect there to be any explicit incompatibility, I
just fear that there may be some issues when using glade3 on glade files
that have been produced by glade2. Either way, I really hope that we
will soon see a ui builder that supports the GtkBuilder format.
Now that we are starting to see GtkBuilder support  in Glade3 can
we finally push it as the "default on-media" package over Glade2?