I’ve automated the customising process of the livecd to a convenient script which can be run on the BT4 Pre final (and future) release. This script sets up a build environment for you and drops you off in a modifiable chroot. You update, upgrade, add, remove packages, and then exit the shell. The script goes on to build a modified iso for you, including the updates and additions you introduced.
The script is very basic, with many elements hard coded (for example, the iso name expected is bt4.iso), but is easily modifiable. In this video demonstration we install the broadcom wireless drivers, to support the Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller (rev 01) card in Macbooks. In addition, we update our backtrack tools to the most recent versions.
The script is available here: http://www.offensive-security.com/bt4-customise.sh