Bjoern Zeeb has updated the jail code (Wikipedia | FBSD Handbook) in freebsd 8-current with the following new futures:
- support of several IP for every jail
- support of IPv6
- Jail can now be created without IP address support
- SCTP is updated inside the jail code
- cpuset is capable to assign processes to a specific jailid or irq
- hostname support for alternative jail names
More information on the complete changes here