Hi there,
this update has been long due. Hans De Goede pitches some of the
features of Bison 2.5 in the upstream monitoring bug report
https://bugzilla.redhat.com/show_bug.cgi?id=704819
... and it's also written in more detail here:
http://lists.gnu.org/archive/html/info-gnu/2011-05/msg00009.html
(and of course in the NEWS file shipped with bison). The bottom line is
that there's quite a few changes. If anything breaks or starts to
misbehave, be sure to ping me.
Thanks,
PM