This week is witnessing a more-than-usual level of activity in the look-and-feel department. In addition to my own announcement on the release 4.0 of Substance, there are a few other items.
The first is the announcement from Fred Lavigne (creator of the Skin look-and-feel) on the updates made to the Javootoo site. The new design is much better, and the navigation bar has been reworked as well. Not to mention that the screenshots and the blurbs on the various libraries have been updated to match the latest respective versions. Here’s how Substance page looks like:

The second announcement comes from Wolfgang Zitzelsberger of Javasoft on the new version of Synthetica look-and-feel. In addition to bugfixes and new client properties, it features a new WhiteVision theme (which uses color combination similar to the Substance Creme skin):

As with all the latest animated themes, this is available under commercial license only.
As a side item, Davide Raccagni has announced a minor release 1.1.1 of his A03 look-and-feel that comes with a version compatible with JDK 5.0. And if you wondered what is the meaning behind the name, go to that link for the explanation.
Update: just as i thought we were done for the week, Jasper posted an entry on Nimbus work in progress:

The release candidate for version 4.0 of Substance look-and-feel (code-named Key Largo) is available. The list of new features includes:
Some applications may need to follow the instructions in the migration guide. Target date for release is September 3. Only defects will be fixed until this date.
As the original Swing Sightings series has lost much of the energy behind it (apart from a few occasional entries on the JavaDesktop page), i have decided to start a new series that will feature screenshots of applications running under Substance look-and-feel. Obviously, not all Swing applications are running under Substance (yet, plans on world domination are currently under review), but there are still some very nice applications out there that use various Substance skins and settings to add some style and spice to their UIs.
First up is LightZone which is a very nice digital image editor. An interesting thing to note in the screenshot (click to see original size) is that this application has quite a few custom controls, all of which are skinned according to the selected Substance skin:

The next one is LinuxSampler which is a pure software audio sampler. This application uses a few custom controls as well; note how well they blend with the core Swing controls painted by Substance:

The next one is Darkstar FX that lets you prototype Java 2D renderers in Javascript. The application suite that contains this tool also bundles the Titanium look and feel that is based on one of the core Substance skins.

The last one is Ixent which provides a framework for non-photorealistic rendering.

Note that all the applications in this entry have decided to use the graphite-based skins which have been modeled after Microsoft’s Expression Blend, Apple’s Aperture and Adobe’s LightRoom.
If you haven’t tried Substance in your application, you’re more than welcome to do so. The current stable release is 3.3, and the next 4.0 version (code-named Key Largo) will be released on September 3rd (release candidate August 20).