Linux distros for Java Development
A real Sun geek would chime in here about the virtues of using Solaris as a Java development platform, but I am much more ambivalent. Developing with Java is about the same on any linux distro; you are going to wind up having to install the JDK and tools of your choosing (Eclipse, Sun Studio, Tomcat, etc) so you may as well choose a distro on other criteria... perhaps how comfortable you are with it, how easy package management is, and if the look & feel suit your development habits are all big factors.
So, to answer your question more directly, a Java developer would do well with any major linux distro that they are comfortable with using in general. If you want some Java goodness out of the box, Fedora 9 and Ubuntu 8.04 have OpenJDK (and NetBeans) according to a recent announcement.
Dont listen to any of these noobs suggesting one distro over another. Java is Java and just about all distros can install java as such:
[package manager command to install] jdk
If the question was about creating RPM's, then obviously RH/CentOS/Fedora would be desirable over deb distros, source distros, or whatever other format you love. However, due to the nature of Java, a specific distro to use is only relevant if the OP cant formulate their own opinion and must follow whatever other people are doing.
To reiterate There is no java distro , use whatever will have you hit the ground running.
// begin hypocritical personal recomendation
... that being said ... I personally use Archlinux. Archlinux works on rolling releases so it is more likely to have a more recent JDK version then the "sudo apt-get dist-upgrade && sleep 6 months" distros of the world.
// end hypocritical personal recomendation
Also, I am fully prepared to get downvoted, but please, leave me above 50 so i can comment still, thanks!
Solaris :)
On a serious note, there is no Linux distro dedicated to Java, so it would be about the same.
OpenSolaris on the other hand (in my very humble experience) would be a bit faster, and you would have bonus of Dtrace as a tool. (Not that you can't find similar tools in Linux, but Dtrace should be somewhat more advanced).