A paper from 8 years ago? Seriously?
Yes. Technology changes quickly, it is true but the principles of communication do not because humans and human wiring don't change nearly as fast as technology does. Newer =/= better.
Web design is a fast-moving field and the topic of credibility and communication of web sites remains key. In this context, I question the 8 year old research as being the best valuable we can get. A lot of work is done in this area and our collective attention is better directed to state of the art.
It would be great to have a more up-to-date version of this research. Unfortunately it isn't on http://www.webcredibility.org/ -- the site referred in the paper.
http://www.useit.com/ is a good resource and they are others.