Implemented. Will show up in 1.3 Alphas a bit after we release 1.2.
But in the meantime, here is how you could enable the option for lan (substitute for the interface optx to opt1, lan, opt2, etc).
*** Welcome to pfSense 1.2-BETA-1-TESTING-SNAPSHOT-04-30-07-pfSense on pfSense ***
LAN -> ed0 -> 192.168.1.20
WAN -> ed1 -> 10.0.250.243(DHCP)
pfSense console setup
0) Logout (SSH only)
1) Assign Interfaces
2) Set LAN IP address
3) Reset webConfigurator password
4) Reset to factory defaults
5) Reboot system
6) Halt system
7) Ping host
8) Shell
9) PFtop
10) Filter Logs
11) Restart webConfigurator
12) pfSense PHP shell
13) Upgrade from console
Enter an option: 12
Starting the pfSense shell system…............
Example commands:
[[snip]]
pfSense shell> multiline
multiline mode enabled. enter EOF on a blank line to execute.
pfSense multiline shell[0]> $config['dhcpd']['lan']['disableauthoritative'] = true;
pfSense multiline shell[1]> write_config();
pfSense multiline shell[2]> print_r($config['dhcpd']['lan']);
pfSense multiline shell[3]> EOF
Array
(
[range] => Array
(
[from] => 192.168.1.100
[to] => 192.168.1.199
)
[disableauthoritative] =>
)