1.- Go to your Turnkey Linux Appliance over SSH or Web SSH and isntall wget (or axel) so you can download the Ruby Enterprise Edition (REE) .deb installer on your box:
I had downloaded Turnkey Wordpress 2.5 a couple of months back and set it up on a a VMware ESX system.
Shortly after installing it, I updated it to 2.8.4 myself following procedures documented on wordpress.org, although now I see that you have released a 2.8.4 appliance.
I do have some minor questions concerning my installation.
1. Is there any way to take advantage of the auto-update/download/delete features now offered for themes, plugins and the core Wordpress? Seems like you need to use FTP, and I don't know if this is even possible with the Turnkey solution.