If the WWE signed Konnan and/or Juvi and placed them on Smackdown then they could recreate the Filthy Animals. I know Konnan's not the greatest wrestler in the world, but it just wouldn't be the Filthy Animals without him. It would give Rey and Kidman something to do, causing mischief. Rey and Konnan or Rey and Kidman or any combo of Rey, Eddie, Kidman, Juvi and Konnan would be another tag team for the dying tag team scene. If something caused them to break up (let's say between Rey and Eddie) then you got some pretty good matches between the two of them ocassionally bringing in Kidman, Juvi and/or Konnan to be the feud enhancer with a tag match. Depends on who turns and leaves the group. WWE could make them heels unless they had an established heel stable already.
For a heel stable, they could give JBL some people to make him the modern Million Dollar Man. Or give Paul Heyman the Dudleys and some other guys who aren't doing much on Smackdown. Stick the Bashams in it if they feel like it. They could probably do the enforcer role pretty good. Or you could put some heels under Teddy Long's care. Some stable battles would probably do some good for Smackdown, because at this point not much can hurt Smackdown. Except giving JBL the title. That would kill Smackdown. They just need to keep throwing shit at the wall to see what sticks.