Wow, surprised there wasn't a thread on this. The demo's up in the PS Store, and the 5 episodes package cost's $20. Spent about 2 minuets in the demo and backed out and bought it! Yup, you can tell it's going to be that good!
Christopher Loyd is back as Doc, and the guy they got to do Marty is a dead ringer.
While I haven't played it, the Dev is Telltale Games, makers of Sam & Max which is highly recommended apparently.