some essential and additional packages, which should be installed after an upgrade

vim
ssh
thunderbird
thunderbird-gnome-support
enigmail
network-manager-openvpn
network-manager-vpnc
nvidia-glx-*
compizconfig-settings-manager
gnome-do
awn-settings
unison-gtk
gimp
acroread

build-essential
git
subversion
rapidsvn
sun-java6-* (uncomment canonical first)
maven2
ant

flashplugin-*
ubuntu-restricted-extras
xine-[ui|plugin]
vlc
libdvdread4
libqt4-dev

a2ps
hplip-gui
gnomebaker
pidgin
skype
gdesklets

virtualbox
vmware
dropbox

texmaker

to be continued …