As revealed by MSNBC the big donorshow was a hoax:
In the last minutes of the program, [“Lisa,” the 37-year-old woman who had been said to have been suffering from a brain tumor] was revealed as a healthy actress and program makers stunned viewers by saying ”The Big Donorshow” was a hoax.
A good discussion of this is over at blog.bioethics.net
Where Kelly Hills questions the ethical acceptability of this as a hoax. The main question seems to be what will the effect of this be. Personally I still think it is an objectionable form of exploitation, now to get huge amounts of free publicity off that back of the appearance of unethical behaviour...