TG2.x is not using CherryPy, so it does not apply here.
In the TG 1.x branch development happens primarily in TG 1.5, which is
already using cherrypy.tree.mount.
I have created ticket #2549 to get this also back into TG 1.1 if it does
not create backward compatibility issues.
TG1.08 is not recommended any more and only gets very serious bug and
security fixes.
-- Christoph