Some possible details have hit the net regarding the new Terminator: Genesis movie in that it will feature alternate timelines as well as revisiting scenes from the original two movies.
Movie Hole received some information from an inside source comparing Terminator: Genesis to the Back To The Future movies.
If you recall in Back To The Future II, they revisited events from the first movie in 1955 etc.
The report states that in Terminator: Genesis, director Alan Taylor will revisit events from the original 1984 Terminator with mention when Arnold first appeared and killed all the different Sarah Connors of that timeline.
It's also said that Terminator: Genesis will revisit the events seen in Terminator 2 with Robert Patrick killing John Connor's foster parents.
Obviously we can see a pattern forming which might imply some sort of alternate timeline developing as a result of something that occurs in Terminator: Genesis.
The report further states characters from both of the original two movies will be appearing as well as new characters that could be used to pass the baton to for the new sequels.
Also included is mention of new scenes from the past with mention of a young Sarah Connors with her parents.
"Terminator Genesis" has a July 1, 2015 release starring Arnold Schwarzenegger, Emilia Clarke as Sarah Connor, Jason Clarke as John Connor and Jai Courtney as Kyle Reese.