That is a quite interesting idea; it could possible solve all these problems with up and down voting which worry so much to so many people. Let's elaborate the idea.

• If someone vote for a node, some karma is given from his or her pool, while it is positive. Therefore, if someone votes, he or she is positively saying that is interested on the node contents.
• The amount of karma received depends on the karma of the giver. Thus, people with highest karma levels would give the higher amount of karma, and viceversa. But this should be done without penalizing to higher karma owners.
• Downvotes could be completely removed from the system. No downvotes, no personality downvoting.
• As giving a vote implies losing own karma, no reason to create and/or use a votebot ever exists.
• Some way to create karma is needed. I can think of a some of them:
  • just making a new node, even if only a small quantity of karma
  • getting a vote in an own node
  • login into perlmonks (as it happens right now)

The result of all these points would be that karma would naturally accumulate in people with the best nodes. At the same time, personality voting and votebots would become unnecesary.

On the other way, a malicious person could abuse the system anyway; apart of creating fake personalities, someone could decide never to vote, thus keeping all his or her karma. A way to avoid this is to "degrade" karma with time, so that karma is lost if not given to others.