Here's the latest version of the Xrandr GUI, that'll be uploaded post-beta.
We've taken care of the major show stopper issues by this point. There's still a few driver-specific xrandr bugs (like lockups when rotating) yet to be sorted out in the coming weeks and months.
You can access this tool via the 'Screen Resolution' link in preferences, or on the command line via 'gnome-display-properties'.
There are obviously still a lot of features to be added, such as being able to lay out multi-head setups. These are in the works, although I'm not certain if they'll be provided by default in Hardy. But I'll be planning on providing updates via a PPA, and possibly we can investigate including it for 8.04.1 if it looks stable and if there is strong interest.
Meanwhile, I've also disabled displayconfig-gtk in the menus. It is still available from the command line (we still need it for bulletproof-X mode). It's become largely obsolete due to Xorg 7.3 autoconfiguration changes, which has resulted in a lot of stuff that used to be set in xorg.conf to no longer be listed there. This confuses displayconfig-gtk greatly, and has been the source of a lot of bug reports and trouble. Further, while displayconfig-gtk has a nice multi-head layout capability, it depends on (the now heavily deprecated) Xinerama, yet these days there are very few drivers that still use Xinerama, so it's become obsolete on this count as well (indeed, you can produce broken xorg.conf's this way). So, the number of people who can still make use of it is becoming quite small, but is not yet negligible, so hopefully having this tool available on the system will still address these users' needs.