The biggest problem with CSS and WSYIWYG is that CSS is a language that primarily defines behavior for the elements in your page - it is not a straight forward drag-and-drop kind of technology. I think a lot of frustration at CSS is that people are still migrating from table-based layouts, which a far more physical representation of your page. CSS relies more on semantic structure of HTML.
CSS layout is all about placing elements in context to the other elements around it. Being able to draw or drag elements around a screen means that such a WYSIWYG editor would either have to make a lot assumptions about your HTML structure, or limit you to certain CSS rules like absolute positioning -- both of which could be very problematic with dynamic content, which is what most of us design for.
I think a handy text editor and Firebug are your best bet for achieving CSS layouts. You're going to want to stay away from anything that uses a proprietary rendering engine (Dreamweaver). Even if you're using something like CSSEdit or TopStyle, which make it easier to write styles and see their results instantly, you're still going to need to know how CSS and box model works to be successful at it.
If you ever go and read the W3C spec, you'll see there's a fair amount of ambiguity written into it. The differences in browsers are very annoying, but it's easy to see why it happens. I've been writing CSS professionally for a few years now, and I would say about 90% of what I write works fine across most browsers on the first try. It can be frustrating, but eventually you get the hang of it and find techniques that work for most things.
