Not a lot of people use it that I know, but it is definitely worth a peek (if even just to try programming in another paradigm, so that you learn to think differently). You’re lucky to be able to take a class that uses Scheme, as most universities these days now teach Java. Here’s a good link if you want to see some lectures from MIT or work on sample problems etc.
MIT Open Courseware – Structure and Interpretation Of Computer Programs
There’s an accompanying book available on-line for free as well (Structure and Interpretation of Computer Programs).
UPDATE:
For those interested in a language that is similar to scheme that makes use of the JVM and can access Java libraries (since lots of universities use Java), check out Clojure. Maybe this will become the new language of choice for computer science introduction (we can all hope!).