ssh - Allow password access for all users except root?

I want to leave the root user enabled on my servers for convenience, and the only reason people are against the idea (that I know of) is brute-force attacks on SSH.

So, is there is a way in SSH to enable password access for all users except root, but allow ssh-key access for root?

OS: Ubuntu Server Edition 10.04 x86

SSH Version: OpenSSH_5.3p1 Debian-3ubuntu7, OpenSSL 0.9.8k 25 Mar 2009

Answer

From the sshd_config(5) man page:

PermitRootLogin
          ...

        If this option is set to “without-password”, password authentica-
        tion is disabled for root.