Wow, first of all, a small (5 MB) download! Taking advantage of more JDK 1.5 libraries. At least on (Unbuntu) Linux, I switched over to using JDK 1.5, so using the new stable version of Tomcat makes sense.
I feel a little like I am being pulled in two directions: I enjoy the new JDK 1.5 language features and performance boosts. On the other hand, I have a long term goal of releasing some of my commercial Java products as Free Software (GPL) and for those, I want to provide both ant build.xml files to build for Sun's JDK 1.5 and unix make files to build using the GNU gcj native Java compiler - so, I need to be just a little careful using new language feature for Free Software releases.