Peter Svensson at Script Uncle has written a very good article on what to expect and how to define a front-end developer.  I have myself worked as interface developer, front-end developer, gui developer, front-end architect, web developer etc etc and I am willing to agree with Peters view on the topic. Today working as a front-end X could be anything, it all depends on what the people hiring you have in mind for today. I really appreciate Peters view on what the expectations are on front-end people when you look in the ads:

Looking at the skill set that the front-end developer should have we find that he or she must be a veteran of all major US armed conflicts since WWII, be able to design, build and fly a commercial airliner, have discovered at least three different cures for cancer (of which at least should have received the nobel price in either of Medicine, Physics or Chemistry) and also be the founder of two or more major schools of painting, including cubism.

It is important the the front-end gets its focus in large projects, and that we do not generalize to much thinking that person A can carry the role of the designer, coder, developer, architect and usability specialist and still do a good job. But on the other hand, front-end stuff is for people who do not understand the complexity of things happening in the back-end of a system. We only do this because we hope that one day we also may write generic server side solutions with xml configuration for creating value objects independent of data source.