I'm evaluating Backbone.js for keeping data and UI synchronized in my web app. However, much of Backbone's value seems to lie in its use of RESTful interfaces. Though I may add server-side backup in the future, my primary use case involves storing all data offline using HTML5 local storage.
Is Backbone overkill for such a use case? If so, is there a better solution, focused solely on updating UI when data changes, and vice versa? (I'm also looking into Knockout and Javascript MVC.)
EDIT: I'm also now looking into Angular.js and jQuery Data Link.