The OS is not hung, since for you to see that output, sshd must have got some user time. Your "it" is ambiguous, but in view of the Subject: I suspect a lot of people will read it as saying that "NetBSD 5" hung, which I don't think is quite fair in this case.
I'm a big fan of reducing ambiguity where possible, and you're right that a hang would usually imply a complete system hang. What would you suggest this be called? A partial hang?
It turns out that an ADB keyboard only gets recognized if it's plugged in at boot time, so I won't be able to get into the debugger. Rats.
John