Is it safe...( Upgrade questions)

I am trying to screw up the courage to update my systems ( 2 macs, 2 fedora ) from
the last 8.4 postgresql updates to the latest 9.0.1 versions.

I have a couple of concerns...

1) I have developed my own gui apps using tcl/tk and wxpython for accessing and
maintaining my db's.

I use psycopg and pgtcl interfaces to libpq.

Do these packages work ok with version 9?

2) The fedora postgresql rpms at pgrpms.org seem to have introduced a new
naming convention and a new directory layout. It is not clear to me what
the impact is going to be with respect to psycopg and pgtcl.

I am guessing that I will have to rebuilt these packages and will not
be able to use the standard Fedora releases.

I guess a third option is to wait for Fedora 14...

Can anyone share their experiences with installing on Fedora 13 ( in particular
the problem with the interfaces with libpq) ?

Thanks

Jerry