yes, actually is at best an overview since many important details are missing (the presentation time was 20 minutes),a a few more are still a work in progress.

Currently implemented in my cluster branch: MIGRATE, and the basic PING/PONG with gossip. I'm working at the rest full time, so I hope to have some alpha to show in two months at max.

Yes, this is antirez's presentation about Redis cluster at a recent Redis meetup: http://twitter.com/antirez/status/28939763430