I've learned how to copy photos from Camera Roll (iPad 2 with iOS 5) to new or existing albums. Is it possible to move photos to new or existing albums from Camera Roll?
No, not straight from the iPad. The Camera Roll is like a smart folder: it contains all items that were stored as pictures on the iPad from apps. You can't move pictures from there to another album, just like you can't move songs from the iTunes library to playlist.
However, if you import the pictures on your computer, then delete it from the iPad (you didn't specify your OS there, but assuming Mac OS X: with iPhoto, it simply asks you whether you'd like to do so after the import is over), syncing the pictures that were in the Camera Roll back onto the iPad will make them appear only in the albums you've configured on your computer, not in the Roll anymore (since they were not added from the iPad).