It's interesting when you can tell from a press release that the studio is being very careful about what they say.
"[Matt] Smith will play a new character with a strong connection to John Connor," is how they phrased it in the announcement today, "alongside Arnold Schwarzenegger, Jason Clarke, Emilia Clarke, Jai Courtney, J.K. Simmons, Dayo Okeniyi, and Byung Hun Lee."
To be fair, they're being very careful about everything involving this film and the cast. They've revealed some basic information. We know that Emilia Clarke is Sarah Connor. We know that Jason Clarke is John Connor. We know that Jai Courtney is Kyle Reese. And we know that Dayo Okeniyi is playing Danny Dyson, the son of Miles Dyson, the man credited with creating Skynet in "Terminator 2: Judgment Day".