I have not had time to look at the new Fireworks and Soundbooth versions, but I’ve been playing a lot with the new Dreamweaver. There is a lot there to like for both designers and developers. As a developer I particularly like the fact that when you open a file it pulls in all of the related/included files. One long-time request they are delivering on is Subversion integration. If you’ve been working with Spry and groaned when you had to generate your data as XML or JSON, you’ll be thrilled to learn you can now generate data sets from HTML tables. Very slick.
One quick warning about these betas. You should note when you check the box to agree to the terms of the download that it will open some text indicating that you have to have an appropriate license to a CS3 product (requirement varies according to which one you are downloading) in order to get a CS4 beta license key, otherwise your playtime with the product is limited to a 2-day grace period. But heck, even if you don’t have the CS3 license, download them and play with them just for the fun of it!