With the CD, you can get as many pictures on it as you have taken. I think on the 4day last week they said there were 46 or 47 different photo opportunities available. We ended up with 100 pictures from our 4 day cruise last week. And they put all the pictures on it, even the ones with your eyes closed, etc.
Unlike PhotoPass at the parks, you can't get any of the borders on the pictures on the CD. But if there are borders you really want (to have a picture that says the cruise name, date, or to get the special borders from the different characters and princesses, etc, after you buy the CD, you can purchase any picture or photo package at 50% of what they're selling it to the folks who don't buy the CD.