This paper / talk was given in 2002, so of course it doesn't tell you what happened with the adoption of, or interest-level in Geometric Algebra (GA) since then

This paper / talk was given in 2002, so of course it doesn't tell you what happened with the adoption of, or interest-level in Geometric Algebra (GA) since then. A quick search on Amazon.com turns up over a dozen recent books using GA in physics, computer science and engineering.