Considering that they're working on a
Beast Wars movie I think it's pretty likely that we're going to get new versions of most of those characters as main-line toys before long. Even if the actual movie designs end up being hideous, Bay-esque monstrosities, it'll probably kindle enough interest to have some more Beast characters in the Generations lines. If you just want the characters I'd say you should wait a bit.
EDIT: Fixed link. I forgot this board doesn't use markdown.