Add me to the "Go see him" brigade.
When my dad was terminally ill, and I mean right at the end, having visitors made his day. Otherwise he was just in the house being ill. Someone from the outside world going in, telling stories/jokes, talking about any old shite was really good for him.
Also, a few people he thought were friends didn't come to visit him, and that hurt him a bit. Some guys he wasn't all that close to did come and visit, right to the very end, and I'll always respect them for that. They really made it better.
Honestly, half an hour and a cup of coffee can make the world of difference at this stage.