This is unfortunate indeed. KDE developers are accusing GNOME developers of not conforming to standards and not collaborating, and Mark Shuttleworth, founder of Canonical, expressed agreement with this view.
The focus seems to be directly related to something called appindicators – and to a larger degree, over the Ubuntu Unity desktop.
The argument goes like this: Canonical and KDE have in the past both approached the GNOME project with ideas, and have been shot down for poor reasons; GNOME refuses to collaborate on projects; others are working together and GNOME refuses.
You can decide for yourself whether this is valid or not. Blog posts have been erupting everywhere on this topic: Dave Neary of GNOME: Has GNOME rejected Canonical help? and Lessons Learned – Aaron Siego of KDE: collaboration’s demise – Mark Shuttleworth of Canonical: Internal competition is healthy, but depends on strong and mature leadership.
Where this conflict will hurt the user is when the user chooses an application: will it work with GNOME or KDE et al? It will also hurt application development as the applications will have to choose – and many will have to choose one technology or the other (not both). This means that applications may only work on one environment or the other – or will have reduced capabilities in one environment or the other. It’s really too bad that the developers can’t come together and work together instead of conflicts like this.