Missing the point of WikiLeaks
economist.com
economist.com
"Of course, those jealously protective of the privileges of unaccountable state power will tell us that people will die if we can read their email, but so what? Different people, maybe more people, will die if we can't."
http://www.economist.com/blogs/democracyinamerica/2010/11/ov...
If (as I suspect) the technology to do what Assange did was available 10 years ago, that is evidence that if Assange had not acted then it might have take a lot longer for someone else to do what he did.
But even if you're leaking to a potentially untrustworthy wikileaks clone, there's technologies that can make it possible. (anonymous remailers, tor (combined with other web anonymizing tech), etc) As more people get used to how the internet works it'll become easier for potential leakers to trust those types of sources.
In other words: it's a bit of hassle to replace him outright. His replacement might be a decentralized system of some sort.