Hmm. It's possible that it could mutate to be a strain that can cause the disease in humans, but it could equally well not. Similarly, a lot of the predictions of how many will die are based on how many died from the 1918-19 epidemic, which might not be all that accurate now as people who were not resistant died and did not pass on those genes to their offspring (similar thing as to why AIDS never became the problem here it was thought it could be - many people here are naturally immune to bubonic plague due to their being descendants of plague survivors and it also confers immunity to AIDS).
From a very clinical (emotionally, not medically) view, even if it did wipe a third of us out, it'd do no end of good to the environment and wildlife. A lot less CO2 emissions, no need to keep encroaching into wildlife habitats, less intesive farming methods needed to feed the remaining people. And lets face it, it can't be worse than mass famines which could well happen if the population growth outstrips food production, which is fairly likely over the next couple of centuries.
And no, I'm volunteering to have bird flu first...
