My colleague Christopher Haupt and I have been working for two years on a Rails-based hosted content management system, and it's recently emerged from Beta. We'd love to hear your feedback: you can sign up for a free account at www.webvanta.com, or watch the intro video at www.webvanta.com/video
(We're the guys who created the Learning Rails online course that you may be familiar with.)
Webvanta uses Rails under the hood (and borrows some stuff from Radiant), but it is designed for folks who want to be able to build dynamic web sites with custom data structures without any back-end programming. We're trying to deliver (part of) the value of Rails to web designers who don't have the time or interest to build Rails apps, and for projects where the budget doesn't support it.
This project arose from custom work we were doing, and the observation that so many of the needs were common across projects. It's taken on a life of its own and is now our full-time business venture.
For now, this is a hosted service only, but we're exploring the possibility of publishing an open-source version.
Thanks for any feedback you can offer.