A fairly interesting match up. I think Douglas' double jab and right cross would give Foreman all kinds of hell. However, Buster was a physical fighter that liked to mix it up on the inside, and while he found success against the bullied Tyson at close quarters, I fear Foreman would make him pay for this approach. This would probably look a bit like the Lyle fight, with Foreman having some bad moments but ultimately scoring the knockout.
Thats roughly how I see it going down too, except Douglas lasts longer than Lyle and steals most of the rounds before Foreman catches him, great summary dude. That being said, Sister Sledge brings up some excellent points too.