RoR and client-side MVC

Hi. RoR does a great job with MVC pattern in the server-side, plus it´s
integrated with great javascript libraries: scriptaculous and prototype,
but these libraries are not mvc frwrks. (not that this is a problem)

It´s yet a relatively new topic, but I think client-side mvc frwrks are
catching up. To name a few:

1. JavascriptMVC:
2. SproutCore:
3. TrimPath Junction:
4. Axiom Stack:
5. Archetype :

And now comes the doubts:

1. Is it really a good idea to use mvc pattern in the client-side?
2. If so, mixing directory structure from some client-side frwrk with
RoR will be very confusing
3. Maybe the best thing is wait until RoR integrate some of this frwrks?

I´d like to hear some personal opinions in this suject.