I've been looking at the site editing demo video and SilverStripe looks really good although I haven't noticed the ability to apply CSS classes to the content without the need to go into HTML mode and manually add the class.
Is there a way to hook up a stylesheet to the editor so that an end user could say highlight some text and assign a class important and it surrounds it with a div or span with that class or adds the class to the container if it is a paragraph for example?
If not, do you think that this is a useful bit of functionality or was it intentionally left out? How would you go about allowing users a bit more formatting freedom that just using heading tags etc?
Download the latest SVN copy and play around with that. The next release 2.3 has upgraded tiny_mce to the latest version and makes doing this type of thing easier. I know what you're asking is a very brought up question, and is suppose to be made easier with the next release of SS.
2.3 should be out by the end of Nov. the last I read.