Oh, and we've moved the XPS 13 Developer Edition to be in the same place as the Windows version. One side affect is that this (well, the internal details of how that's done in our catalog) makes it easier for us to change up the Dev Ed config options. You can use the OS filter drop-down just above the config carousel to narrow down to only the Ubuntu configs.

That's the URL for one of the older versions. In general dell.com/sputnik (same as dell.com/developers) will get you to the current systems.