Good sysadmins, yes. Keep in mind that the ideal sysadmin is someone who knows the guts of BSD or Linux (typically, not both) inside and out; can troubleshoot the strangest of problems very quickly; is constantly measuring and improving performance; and can hack together shell scripts or Python or even C code as needed.
Linux and BSD are hellaciously complex and prone to very strange behavior once you start taking them into high-performance land.
If you're OK settling with, "can read syslog and look stuff up on the web", those guys are cheap.
Hmm. I have to think about that a bit. On the face of it, EC2 and colocation require completely different skill sets, and those skill sets don't overlap very much.
Being a good Linux sysadmin might be fundamentally harder than being a good EC2 sysadmin; I'm not honestly familiar enough with EC2 to know.
I would point out though that Amazon has a vested interest in making EC2 less hard, so I would be surprised if the general opinion was that EC2 administration was just as hard as Linux administration.
EC2 instances are running some OS, whether it's Linux or BSD or Windows or whatever. The only thing that doesn't overlap is hardware tuning and maintenance, and even there you should be using the same tools to figure out if you've got a hardware bottleneck on your EC2 instance as you'd use to evaluate performance on a standalone box.
Linux and BSD are hellaciously complex and prone to very strange behavior once you start taking them into high-performance land.
If you're OK settling with, "can read syslog and look stuff up on the web", those guys are cheap.