Chris Fahey explores the question of whether or not designers need to be technical in order to be successful in interactive design.

Instead, I think a firm grounding in a broad range of designed experiences far outweighs any need for hands-on experience in the deepest challenges of technology implementation.

I agree with Chris to an extent, but think that the ability to understand obstacles toward implementing a given design is the difference between the designer who creates great stuff, and the designer who creates great stuff that you can actually use.

I’ve never seen a designer get any worse after spending mental effort becoming familiar with the more technical side of the web.