Dell do not need an existing standard to start selling Linux Desktops. Dell only need to make a decision on what is the default: a default distro, and a default desktop environment. They do not need to support every single distro or desktop environment or editor or browser under the sun, just the default. Anybody having special requirements on distro or desktop environment or anything will pretty much be able to figure out how to customize their own environment. This will also create a huge amount of opportunities for third-party support providers, which is good for business and open source.