We've just released the December CTP of Expression Blend (new name of Interactive Designer) and Expression Design (new name of Graphic Designer). Also, Web is now a released product, so you can download the trial to use it yourself.
This December CTP marks a new milestone in the Expression product line, which can be observed in the completely redesigned UI. Both Design and Blend have a very unique new design-oriented interface, which breaks away from the traditional mold. The most obvious difference is the fact that it's... quite dark. The tools and everything but the canvas are very dark colours, which seem to be designed in such a way as to provide minimal obtrusiveness and distraction from your work. They are easy to see when you're looking for them, but when you're focusing on your "canvas", they don't get in your way.
Since there are large changes in both these products, many of the features from the previous release are temporarily gone, as they are revamped. Also, be warned that graphics you created in the September CTP of Design (Graphic Designer) will not necessarily import correctly in the December CTP. Since some of the old effects have not yet been implemented, your September CTP images will often be missing these applied effects.
An entirely new product has also been introduced into the Expression Studio, which is Expression Media, a tool for the import, enhancement, and publishing of rich video optimized for the web.
A huge new milestone has also been reached with WPF/e (Windows Presentation Foundation Everywhere). WPF/e is a plugin for cross-platform and cross-browser support of WPF content, (such as content published with Expression Media and Expression Design). This really opens up the boundaries in terms of internet deployment, not just local Windows use for the UI and content you create. Developers should also be pretty interested to know they can use AJAX and ASP.NetAJAX to ceate interactive content for WPF/e.
Check out the releases, but keep in mind they're evaluation only. I've been playing with Blend for a while now, and I'm curious to see feedback from everyone in the community. Some of the early reports are coming up very positive already, so I'm excited to see what people can do with them!