Dave Jarvis has released version 1.0.0 of his Audio Analysis script. This script will read a .wav file and map the amplitude to several types of IPO curves. It's a great tool for synchronising certain effects (like thunder and lighting, explosions etc) in your animation with the audio.
Dave also provides a tutorial, so you should be all set to experiment with this.
When I tried the script the Analysis step didn't seem to work 100% - it spits out some errors and then aborts. I have a feeling that it's due to the type of .wav files that I tried to process.If I may suggest some improvements, it would be cool to add spectrum analysis options so that you could use certain frequency ranges to drive certain parts of your animation (like using the bass for one part and the high tones for others). I also found that entering the .wav filename by hand was a bit cumbersome. Maybe there's a way to use Blender's file select window for this?
Note: If you're a Mac user, use the following command to move stuff into your Blender scripts directory:
mv * /Applications/Blender/Blender.app/Contents/MacOS/.blender/scripts/