I've been interested in ICEfaces for a while now, and been pleased to see how the adoption is coming along.
Being built on the JSF framework, ICEfaces is a first-class citizen in the JEE world and integrates well with just about any other Java framework. (It can even play nice with a surprizing amount of other JSF component frameworks, like Apache My Faces.)
On top of this, their IDE integration is top notch, supporting just about anything in common use today. After using Eclipse for a while now, I've recently moved to NetBeans due to my new role. Thank goodness the ICEfaces IDE support module is there!
Recently I have had the pleasure of re-aquainting myself with ICEfaces. I finally got the job I've been hoping for since my first brush with JSF a few years back. I'm now a UI architect and it's fantastic to have the company respecting my opinion that ICEfaces/Facelets/JSF is the way to go for enterprise rich internet application (RIA) development.
I even got the opportunity to take my new team on an ICEsoft training course to get them excited about the possibilities. The people at ICEsoft have a great, open approach. They are interested primarily in productivity, and gave all kinds of ideas in how to best use their framework and how to best utilize other tools to be productive. In two days they were saying things like "that's so cool", "this is how web app development should be" and "I'm never going anywhere near Struts again". In ICEfaces, you hardly ever have to think about the request and what values it's sending. You're thinking in terms of components and objects and services - that's the way OO development should be.
Well that's it for now. Take my advice, the next time you think about doing a Java Web App, evaluate ICEfaces. (And don't just look at the component showcase, evaluate the whole framework.) You may find it very enlightening.