Findings:

(1)
TOPIC(S) -> SITE MESH, TOMCAT, WEBLOGIC, DECORATORS.XML

Here are some findings of mine regarding SiteMesh on Tomcat 5 vs. Weblogic 8.1sp2 when used in conjunction with Struts.
Both work fine, but here are some nuances with the way the app servers handle the filters that you might find useful:

This mainly concerns the decorators.xml file.
My sitemesh servlet is mapped in web.xml as *.do.
On tomcat I can use either .do or / in my decorators.xml file.
On weblogic I must use /* in the decorators.xml file!!!! Using *.do does not work because weblogic has already resolved the foo.do to bar.jsp by this point.

Additionally, this means that if the you have /one/* and /two/* in tomcat, this will work fine. However, on weblogic, if /two/foo.do resolves to a jsp in say the /one directory,
then the request comes through as /one/bar.jsp and the second pattern is not a match, like it is on tomcat. I have no preference of one app server over the other, but it is annoying that they are handled differently because now my decorators.xml file has to be altered when porting applications.

Note, that I could map to two site mesh servlets in my web.xml file to avoid this problem, but that somewhat defeats the purpose of the decorators.xml file.