Well, I can't fault him on his look:
That shirt is amazing, and it's working with the whole Old Testament thing he's got going on with the beard and the pony tail. That's a look that says, "I'm so powerful I'm never going to have to answer anyone ever again." It's like how people with face tattoos are scary: you know that they have made a decision -- probably a well-reasoned and conscious one, at that -- to never bother reentering the workforce and becoming a functional member of society and so forth ever again. Then again, people with face tattoos have got good reasons to expel themselves from society: they know they'll do much better, over all, on the outskirts of this embarrassing civilization, the one that gave birth to a glorified Youtube channel that tags its videos, without irony, as persuasive, courageous, ingenious, fascinating, inspiring, beautiful, funny, and informative.
This man, on the other hand, is doing alright in this ridiculous world, having the honor of appearing in three TED Talks, and why shouldn't he? He tells people what they want to hear, and can get away with acting like he's the pioneering vanguard of immortality because he dresses like a well-polished junkie. The fact he has no explanation how we're going to reach this plateau of humanity is immaterial, because he spends the whole of his screen time describing everything but how we actually stop the ugly dying business he's always whinging on about. There are persuasive moral arguments, there is dispelling of pipe-dream exoduses from Earth, there is even a charming explanation of how those alive today might live long enough to enjoy a life that lasts until you manage to get hit by a bus some time eons from now.
But, the naysayers! These people, they rob the future of the right to live forever because they can't deal with these ethical implications he so deftly addresses. The fact that this science does not exist yet does not seem to bother him, and he shoos this minor logistical issue away with the history of flight. Planes, you see, were the stuff of dreams for quite a long while, until Orville and Wilbur sorted out how to build one. Not so long after that, we have supersonic jets and Virgin Atlantic with complementary headphones (do they still do that?) and thus, immortality.
Better evidence for immortality exists in his two following talks. Not in his words, but he does look much better in the following videos, the latter of which was four years later. Maybe it was the harsh lighting, I can't say.
At the TEDMED conference, de Grey may be acknowledging the reality that it wasn't the think-of-the-children business that was stopping people from taking him seriously, so he ups his ante with some fire-and-brimstone. Aging, you see, is just terrible. Nobody should have to go through that, and the only reason we put up with it is because nobody can imagine a solution. This, of course, is absolutely true, which is why the world rebelled against dishwasher research in the 1800's; why dream of a world without the drudgery of dish washing when science had all but failed to cast this horrible endeavor as but a memory of a crueler world long ago.
And yet, he closes by emphasizing that bringing about serious research to achieve immortality is but a side-effect of what he is actually doing: working to stop people from getting old. It's a stupid distinction, and reflects the fact he doesn't understand that people think he's nuts because he's talking about making people live forever without any idea of how to pull that off, not that the media is sullying his reputation by making him look like a crackpot.
In 2013, he's got it! People just don't understand what aging is! Aging, he says, is the accumulation of damage. Now, will you idiots respect me?
There's a sadness in these videos. He thinks himself a messiah, and thinks that he is alone in his mission because he's surrounded by cowards. The desperation reeks: from stupid questions ("Who would like to have Alzheimer's"), insulting his audience, ("Nobody cares about their children!"), and accusing them of pessimism. "That's why I have to give these talks," he moans. We are faced with a tragic combination of a man unable to comes to terms with his mortality and an international platform with which to proclaim his denial.