Upgrading from 1.9: Follow the upgrade notifications in Gnome. There's no need to download the 2.0 CD.
is no longer supported, and is not getting security updates. If you
still want to use deltad for some reason, you should change your
sources.list to point to http://archive.gnewsense.org/gnewsense-deltad/. Note that this is not recommended.
There is currently no upgrade path from deltad to deltah. If you want to switch, a reinstall will be required.