[kevinreedy]

I'm not in the beta, and thus haven't been able to play with it yet. But, I don't believe there'd be anything prohibiting you from generating the certs on a separate machine. In fact, I'd imagine that's what you'd want to do (if you have more than one server) rather than generating a separate certificate for every web server or load balancer.

[pfg]

That's correct. I've recently deployed LE on a side project. The official letsencrypt client supports a mode called webroot, where you basically tell the client where your webroot is located on your file system, and it will place a file in .well-known/acme-challenge/<random> to confirm ownership. I use nginx in front of multiple domains with different backends (which do not all have the platform equivalent of a webroot), so I simply added a location directive for .well-known to all vhosts pointing to the same directory which I then pass to letsencrypt.

It would be trivial to move this to a separate machine by using a reverse proxy for .well-known instead of serving it directly from your load balancer's filesystem. The rest is just scp'ing your certificates and keys to your load balancers (or using your configuration management software of choice to achieve the same). With ACME being an open protocol it's quite likely that someone will end up writing a client specifically for this use-case, making it even easier.