I will do some clarifying for John, because I forgot about Adobe Premiere Elements.
It's actually a really nice little video editing application. It's like Windows Movie Maker on steroids, and 3x more efficient. I used to use it in conjunction with AAE. This was because the older versions of AAE didn't provide audio playback when viewing or pre-rendering a sample... so I'd do all the heavy effect editing in AAE and import it in APE.
If you're looking for generic video editing that comes with a LOT of unique and super-great features, APE is an excellent application. It's a lot more powerful than Windows Movie Maker and iMovie, and also has a very high compatibility list. It even has light keying, which unfortunately is predefined. However, if you're working with greenscreens or bluescreens and you're light keying, you shouldn't be falling back to APE as your main source of editing.
Photoshop is an interesting choice for video editing, John...
I don't know why you'd ever use it unless you're making animations. And even then, if you're going to use it for video editing, you should infinitely just stick with AAE... because it can do everything (and more) that PS can do, and ten times better.
