There's a big gotcha waiting for anyone who has processed lots of RAW photos through Lightroom 1 or 2 or through Adobe Camera Raw prior to version 6. Adobe introduced process version in CS5, ACR 6, and the Lightroom 3 public beta.
What does this bit of jargon mean? Well, it means that Adobe has introduced a whole new way of reading RAW data.
If you've followed the public beta of Lightroom 3, you probably know that you can export your slideshow with music. Well, as Scott Kelby points out, there are a couple of other features for embedding sound that users are going to like.