Since I am working on quite some sites for myself, I was quite interested when I read the Steer CMS announcement on the symfony-users mailinglist. I took some time to evaluate it, specifically for symfony-framework.nl . And even though I decided against migrating to Steer CMS, I am still mighty impressed by the work the Steer developers have put into it and the product they've been able to present.
Steer is highly customizable. It offers a basic and very interesting system of maintaining regular content, as well as a weblog system and event calendar. Another great idea is the idea of being able to create themes simply by having a theme be a plugin. This will make it very easy to install new themes into a website.
One thing though that still needs quite some work is the documentation. Granted, when you're used to the quality and abundance of the symfony documentation, other projects will have a hard time to come near to it. Yet, the Steer documentation is still a bit limited.
But, it's not that weird. Steer CMS is only available as version 0.1.0, so there's still much coming. And given that fact, I think Steer CMS will have a big future in the open source CMS world. I am 99% sure I will use Steer at some point in the future for a website.