Fred Thompson to Run in 2008?

I've always liked Fred Thompson and he has a very strong presence, both as a politician and as an actor. Now I see there are some hints he may run in 2008 (via Instapundit).

After seeing the news about Dick Cheney yesterday I got to thinking about the possibility he may step down at some point due to ill health and I wondered who Bush could possibly replace him with. Ruling out any current candidates and not considering any of the current crop of senators or congressman, the idea of Thompson crossed my mind. I think he's respected enough to be an easy sell and he's got instant recognition.

Is it conceivable the White House could pick him under that scenario whereby he then has the power of the office to be the heir apparent?

Wild specuation, I know. But food for thought.