Get in touch with low latency people from Sun, IBM or RedHat? 
fultonm: My name is Mike Fulton and I am the lead architect for WebSphere Real Time, which is a real-time Java runtime environment for use on Linux and AIX. 
We provide real-time technology in our JVM, including Metronome (already mentioned) for improved determinism, improvements to our JIT compiler to reduce jitter, support for ahead-of-time compilation, if you want to completely eliminate the variability of a runtime java compiler, as well as full support for RTSJ - the real-time specification for java (and a bunch more stuff that I'd be happy to talk about)My id is fultonm@ca.ibm.com