The key concept of a Jini network is the
federation.
The Jini
protocol allows
clients to advertise their services ("Hi! I'm a printer"), and more importantly, to locate each other without the need of a central
server/
single point of failure (a la
Napster, for example).
Sun seem to be aiming this at
embedded devices ,
mobile phones in particular.
A lot of earlier Java innovations ( mobile code objects a.k.a. applets, RMI) seem to have been designed with this in mind.
Bill Joy in particular sees the Jini federation as a 'network BIOS' for devices to find each other, and James Gosling has confessed to have had Jini in mind back in 1995 when the Java language was created.
Either Sun are very lucky, or they are a lot more cunning than people give them credit for.