I came across this article today, which I thought others might find interesting as well: JSF 2.0 and Tomcat. It looks like integrating the two is not as nice as I would have assumed it to be but it can be done—you just won't be able to go live with it if you brag about it to the Ops guys. Cay does, however, suggest looking into Glassfish instead of trying to integrate it with tomcat 6 but he does detail all the painful steps necessary to get it working. Alternatively, beta-fresh JBoss Web Server 3.0 provides a JSF 2.0 implementation as well if you are more comfortable with JBoss and want to get your feet wet with JSF2 now.
Also, while visiting the Sun developer site, I discovered this "Introducing JSF 2.0 Tour" (login required) screencast by Sun Senior Staff Engineer Ed Burns that provides an overview of all the neat new things in JSF 2.0. I'm watching it now!
DISCLAIMER: I do not suggest going live with anything in beta because, ultimately, I'm an Infrastructure and Operations guy but I can't imagine the beta cycle for JBoss Web Server 3 being all that long of a wait. So if you want to see what JSF2 is about now, you could certainly give the beta a test drive now while waiting for JBoss Web (or JBoss AS6) to go GA.
In addition, I do not suggest switching to Glassfish or JBoss either from whatever you might be using unless your company is willing to fund a support contract during the development stages and for at least the first year after going live. Just because something is open source and freely downloadable does not make it any less complex than a commercial solution.