Over at Second City Style might have hit the nail on the head when it comes to the iteration of celebrity "designers"...
Fashion Manifesto: Why Celebrities Should End Their Affair with Fashion Design
What do you think?
(Don't get me wrong...I have found pieces of some worth in some of these celebrity lines (see my review of the M by Madonna line). But I too find it disturbing that celebrity lines are taking up the air that those who are truly designing clothing could be breathing - and perhaps coming up with truly innovative designs.)