Just for the record, I can confirm that Broadcom wireless cards *do*
work in Lucid and Maverick (I have one in my Dell), but you can't use
them from a live CD, partly because, as you say, you need an internet
connection to download and install the driver, but mainly because you
then need to reboot the PC, which wipes out all that effort :-)

As Broadcom drivers are non-free, I would be surprised if many distros
will ever include them by default on their live CD; it's very
interesting that Dreamlinux apparently does. However, as Broadcom seems
to have recently changed its mind and embraced all things Linux, there
may well be hope for some quality, open and free drivers in the future.