The big publishers are coming together to build the Fair Syndication Consortium to fight sploggers and online plagiarism (via Erick Schonfeld). While solutions in the past have tried to modify the content or syndication to fight sploggers, the consortium aims to eliminate the root cause. The consortium wants to negotiate with the ad networks to pay them for their content being reproduced elsewhere.
I think this solution has the best chance to discourage sploggers as it tries to eliminate the reason why they exist. If it works, even the small publishers will stand to gain a lot along with the big fishes. However, collaboration with the ad networks will play an important role here. Maybe the consortium should ask the ad networks as well to participate in this.