is not whether a single distro survives as the dominant one, but whether there can be an established standard, a specification for ISVs to refer to when they want to deploy on GNU/Linux distributions. The fact that many distributions have different configurations/places to store their prefs, have different package management systems and so on, makes it difficult for ISVs to test their stuff and deploy on a platform. For instance, if I wanted to release Photoshop on Linux what do I tell my clients? Requires glib v2.4 and above, GTK 2.12 and above, GNOME 2.22 or later, blah blah... isn't it easier to say Fedora 11 and above? or is it better to say requires LDB (Linux Desktop Base) 1.1 (like LSB only more desktop oriented). The LDB should even define some way for the app to list its dependencies so they can be automatically installed by packagekit, aptitude, or whatever. I could then, just test the product on a single LDB platform and presto! I have a single platform to support, no problems (ok I am simplifying this a little).
Anyway, say no to a single distro, say no to a single desktop; diversity is the strength of libre/open source .. there just needs to be some work on interoperability and we are done.