I've noticed a lot of people say they have or would like to get a standalone cd player, headphone amp, and headphones. So no real amp or receiver is needed for this setup? Pardon my ignorance, it just seems strange at first. What happens then if you wanted to connect real speakers, the headphone amp wouldn't be enough, right?
Yes this would not be enough. You will have to get a separate speaker amp for your speakers & a switchbox if your CDP does not have multiple outputs.
In my room, there are no separate speakers for my computer or DVD (except for the bass shakers under my chair). My DVD uses a headphone amp & headphones while my computer has a headphone directly connected to the soundcard.