Many modern operating systems support two kinds of timers, a "regular" low resolution one with a maximal tolerance in 10s to 100s of MS and a "high resolution" timer with a much finer resolution. (In windows this is called the "multi-media timer" and is aprt of the Windows multi-media extensions.) This high-resolution timer is essential for game and multi-media apps where fine timing is often essential and is oen of the most requested new Java features among game developers.
The API would most likely look like our current Timer API but have a higher resolution. Additionally there would be a call to determine the actual resolution of the high-res timer on the given VM/host platform combination.
The importance of this feature cannot be over-stated. The 99% pure Java game Roboforge would have been 100% pure but at the end they had to put in native code to talk to the high-res timer themselves.