I suspect however that you are thinking of the donation pool as a fixed one, rather than a flexible one. It seems likely that having a face, a name and a story will cause people to engage and ultimately donate more. Donor fatigue ( http://en.wikipedia.org/wiki/Donor_fatigue ) is a very real thing, and specific interactions with specific recipients that have visible outcomes to the donor on a human scale do a lot to avoid it.
So the question really becomes:
Is it ok to let the photogenic people be more likely to get treatment if it means more people get treatment overall?
Is it ok to let folks sit in judgment if it means they will save more people as a result.
I think we all have to come to our own conclusions. I for one am blown away by what this site is doing. I'm willing to let the photogenic do better than normal if it means more personal engagement.
I also think that we all make choices about who we help live and who we leave to suffer every day. Relegating those choices to chance doesn't seem to me to be any more moral than selecting on other criteria. In fact it's something you are already forced to do because their are several different charities out their to choose between.