Alright, no one answered, but I'll respond to myself in case someone looks at this thread for reference.
Took the COMPASS mathematics test today. Basically, the content on the test is very similar to the content on their sample test. Fairly basic. No need to memorize all the trig identities or anything. (There are a few questions to this effect, but they are all 45, 30, or 60 degree angles or similar, so you can muscle through it without actually remembering the identities.) I'm 33 and haven't taken a math class in nearly 15 years, did a few weeks of review, and passed easily into Calculus (which is as high as this exam will place you.) If you are freshly from school and took Algebra II and Trig and paid attention you should have no problem with this test.