Good software for a simple, slide-show style video presentation?
So, I ended up using Prezi to run a presentation and camtasia studio to record it and render it to the video file I needed. Both were 30 day free trials, so that worked out nicely. 

I put all the audio in Prezi (It lets you add background music for the whole presentation as well as voice overs on a slide-by-slide basis) but I could have just easily have done it in camtasia.

I needed the voice overs for timing in the Prezi, which is why I did it that way, but there's nothing stopping you from just putting them in anyway, and removing the sound when it gets to camtasia, and putting them in as separate tracks. You'd probably have better control of volume, etc, that way.