I think a lot depends on who and why you are building a website for. Internet marketing has become far to complex to generalize. For example:

1. The majority of our customers want and can only afford "brochureware". Graphic design is by far more important as they want people to like what they see and send them an email asking for more.

2. Others want to and can afford to provide information in a database. Then development becomes very important, but is useless unless it is easy to use (i.e. good design).

All in all, I think a developer has an advantage, because he can learn clean, uncomplicated, unsophisticated navigational design with kickass programming.

But don't get me wrong, both are needed, as one without the other is still a bad website that won't accomplish its objectives.