Oddly enough, the answer to that question ("What's really going on with JBoss?") is probably best answered by someone outside Red Hat: Marc Fleury. Marc isn't shackled by the need to keep corporate secrets, though perhaps he's a little biased.
Marc offers several data points that suggest that JBoss adoption and monetization is "going through the roof." But he also takes on two potential aspirants to the JBoss throne: Ruby on Rails and SpringSource (I've sanitized Marc's comments to suit my Puritan sensibilities):
...Three projects, three different life stages. As a colleague put it: JBoss is a [good looking mom]. She is aging well, she's beautiful, and the children (projects like JBoss Seam and BlackTie), are doing just fine thank-you-very-much. On the cover of every magazine, RoR is the hot new thing. It's eighteen, it's perky and oh, that sexy pout! The excitable fringe is just in lust. Meanwhile, Spring is getting a little longer in the tooth, and after dinner and a movie (training), there is really not much people need to stick around for (like a product subscription). So she gets a boob job (aka Covalent).
After talking with Peter Fenton about SpringSource, I think it has a long life ahead of it, "breast implants" or not. But I also think it's important to remember something that Marc says: a lack of media coverage doesn't translate into a lack of commercial success. In fact, sometimes it's the exact opposite: the bigger the customers you're signing, the less likely it is that you're going to be able to talk about them publicly.
JBoss has a long and fruitful life ahead of it. JBoss is well into its monetization phase - the prime of life when it will make the most money for Red Hat. It doesn't need to figure out the business model any more. People are happily paying for services (certification, JBoss Operations Network, support, etc.) around it.
It's a good time to be JBoss. It's a good time to be Red Hat. JBoss has been de-risked. It is now time to monetize it fully.