As Ebert says, communicating online as we are now, no one has to wait for the other to find a way to articulate his intent. It's an interesting point. If Roger were actually posting here, we wouldn't even know of his disability.
I was very much impressed by the sample of Ebert 2.0's voice, sampled from his own speech and implemented by some outfit in Scotland. The intonation is not quite right, as Roger notes, but I thought it was quite easy to adapt to, as a listener, and it was much more expressive than Alex.
The technical explanation of what, exactly, prevents him from speaking any longer, seemed wanting. He said something about not being able to maintain an air seal, but we've probably all heard people with laryngectomies speaking with those clever little vibrators (from Bell Labs?) pressed to their throats which produce a square wave vibration to substitute for what the larynx can no longer do. I guess they had to remove too much of Roger's articulatory tract for that to work.