Thought #1 - It might be nice to see a breakdown of the reputation of a 'controversial' node, with both ++ and -- votes (say a node with more than one of both). It's quite likely that such a node merits further discussion :-)

Thought #2 - You can vote on a node, no matter how ancient it is. I suspect people very rarely vote on a node once it gets old. As the reputation of a node may be useful in helping someone searching the archives for an answer to a question, it would be good if the voting system timed out, and you could see the reputation for all nodes over, say, one month old, but no longer vote on them.