My new (non-Seam) project is very large (to give you an idea we have approx. 900 JSPs!) My previous Seam project consisted of no more than 10 JSFs. This project is a commercial software that is used for emergency notification services via phone, fax, email, etc.
Here are the frameworks that are currently utilized in this project:
1) OC4J 10.1.2 app server (J2EE 1.3 certified)
2) Struts 1.1
3) Struts 2.0
6) Oracle JBO (ADF?)
We have three JDKs installed on our workstations (1.4, 5 and 6). The app runs on Java 1.4 but Eclipse 3.5 requires 5 and they throw in JDK 6 for some other newer apps.
We may be possibly introducing JSF and Hibernate into the mix next year.
I used to think that the JBoss dev stack was initimidating. Not anymore...
It's sad that everytime you change jobs/projects to a different company as a Java developer, you must essentially re-learn a new dev stack/APIs.
Also, it's much easier to use ORM tools like Hibernate when you're starting from scratch using top-down or bottom-up approach b/c you can tweak the hell out of your Java entity classes and/or db schema. When dealing with a legacy schema, it's more difficult so that's why we're leaning towards continued use of iBATIS rather than Hibernate.