I passed the 70-100 exam a little over a year ago. As everyone else, I expected to find all I needed for the exam -- or at least 80% of it -- in the MS-Press training kit. Although the book is very interesting and informative, it hardly covers 30% of the material you need to know on the test. For one, I can't remember a single question on the exam regarding the MSF. It looks like Brian didn't take the exam yet, for he asserts that knowledge of the MSF is required for the exam. It's a bold lie.
What you do need to know for the exam are the following:
-Database Design, including Normalizing.
-Reading carefully business requirements and understanding how to translate it into technical specs.
-Drawing a workflow/dataflow chart.
-Thorough apprehension of MS technologies and when to use what.
If you are seriously about the exam, I strongly suggest that you get the Transcender simulater.
P.S. Keep in mind that with the release of the .Net Framework and VS.Net there will be a huge paradigm shift in the way of requirements and solutions. Therefore, you should rather put more effort into learning the .Net framework.