"Also, will it break on older dists? lucid? hardy? (i auto-backport everything down to hardy by default)"
@Fabien: Yes, if possible this really needs to be a distro-patch for now. The resize grip feature has landed upstream in GTK+ 3.0, but I backported it to 2.x for Natty. It's not possible to backport it to older distros at this point though.
"Also, will it break on older dists? lucid? hardy? (i auto-backport everything down to hardy by default)"
@Fabien: Yes, if possible this really needs to be a distro-patch for now. The resize grip feature has landed upstream in GTK+ 3.0, but I backported it to 2.x for Natty. It's not possible to backport it to older distros at this point though.