There's a difference between a "html editor" and a "richtext editor".
Think of richtext as an xml document in the developers predefined format, however using the functionality in that richtextbox control (Cheers Dan for making such an awsome control) ... you can export the richtext xml and then xsl transform it to html.
It's not the cleanest way I've ever seen it done but for free you can't expect the planet to bend over backwards just for you can you now ;)
I dabble in ...
SOA, WCF, Silverlight, XNA, ASP.NET.
... Come visit me @ www.ccoder.co.uk
My current setup ...
Dell XPS M1730 with Windows 7
Raid and SLI in a laptop with the latest from Microsoft, what more could a propgrammer want !