Don't get me wrong, Neil deGrasse Tyson is a brilliant guy, and he's doing more for science education than almost anyone else alive today, but Sagan had a real talent for being profoundly inspiring on a deeper level.
He has an amazing talent to boil down complex science into engaging communications that regular 'ol folks like myself can understand, yet still rich enough as to make me think about the topic for a terribly long time afterwards.
I was in high school when I got the news that he had died. Having grown up treasuring a hardback copy of Cosmos that my parents had got for me when I was 5 or so (still on my bookshelf today of course), I had fallen immediately in love with the phenomenal PBS series of the book and looked up to Carl Sagan as someone very special indeed. It was no wonder that my parents helped me to become a member of Carl Sagan's Planetary Society back in grade school, a membership I held all through high school.
In utter shock and disbelief when I received his news, I remember I had been walking to our school's computer lab. By the time I reached it, my brain was numb and I just sort of walked aimlessly to a computer along the south wall. As I approached the desk, I told our lab teacher what I had just learned, sat down, put my head in my hands, and cried.
Looking back on it now, I'm still not entirely sure why news of his death had so profound an effect on me, but I suspect it had something to do with Carl Sagan's "real talent for being profoundly inspiring on a deeper level," as burke so eloquently pointed out.
EDIT: Just finished watching the three videos. Absolutely blown away. And no, it's not really a mystery why he had so profound an effect on so many: between the eloquence of his words and his hypnotic speech and diction, who couldn't help but we swept away by his lessons? Only he could render in such convincing detail "the view that Kepler dreamed of," (if you have a copy of Cosmos lying around, you'll recognize that particular caption's stunning photo), and so much more in the universe beyond.
It similarly uses quotes from Sagan's audiobooks, but combines it with the Lost soundtrack (which fits surprisingly well), and footage from Discovery and the BBC. Really great stuff!
I was lucky to have come across Carl Sagan and his books in my early 20s. The amount of positive inspiration this has provided me couldn't have originated anywhere else. He's definitely one of the writers who influenced my world-views the most.
SETI only went into hibernation a few days ago, and I wouldn't bet against them getting the money they need to get back up and running again soon. And even if they're not operating for a little while, the technology continues to advance. Don't be dispirited!
Carl Sagan is one of those people.
The young people he inspired to choose careers in science, or just to have a love of science that makes our society stronger, are innumerable.
I hope that kids growing up today have role models as amazing as Dr. Sagan.