Hi harpooninvestor, thanks fo the message! We can do one better than a Witness biography - we can put you in direct contact with them. Head over to the Peerplays Witness channel on Telegram, where you can talk to them in real time.
The Peerplays blockchain has been up and running for some time now. Bookie Beta Phase 1 recently finished and the DApp will launch this Spring. Currently, you can play Rock, Paper, Scissors over at www.helmbet.com, and there are more DApps in development by third party companies that will launch in 2018, too. We recommend visiting the Peerplays Telegram channel for more info. They're great at providing insight and answering big questions.
RE: What is a Peerplays Witness?