I've created two posts with proposals, but it is very much up in the air right now.
This is a very simple proposal, although it does not get into actual 'guilds'. It would just be allowing whales to delegate their voting power to another user:
https://steemit.com/curation/@timcliff/human-vs-bot-curators-introducing-human-competition-into-the-equation-allow-whales-to-delegate-curation-power-to-dolphins-and
Here are thoughts on actual curation guilds:
https://steemit.com/curation-guilds/@timcliff/thoughts-for-curation-guilds