I think "Born to Run" is a fitting end to the series. It links up with the new terminator Salvation film explaining how John in the upcoming film is much younger the the future John Connor seen in T1 and T2.
They finally revealed Weaver's motives and John Henry's purpose. That kind of wraps everything up nicely. It was good to see that Derek, Allison (Cameron) and even John's father Kyle all exist in the future. It keeps alive the possibility that the show may continue. I hate shows that kill off their main characters when they end just to make the finale more shocking or exciting.
Earlier in the season Cameron did appear to hint that she could provide female companionship instead of the Riley girl. So I thought the writer's might take the opportunity of Sarah's absence to explore this avenue. Afterall the Vick cyborg had a human wife! The way they did it was a bit of a cop-out, having Cameron ask John to get on top of her and check her insides for radiation leakage. I'd liked to have been there when they came up with that idea.
There did seem to be at least one inconsistancy in the series story line. In the pilot episode of season 1, when Cromati was breaking into the bank vault he had a quarter of his metal head exposed. When he was shot with the radioactive laser gun his head came off exposing even more of his metal body, and his head came through the time bubble with no skin on it at all . How is that Cameron's body couldn't go through the time bubble in the finale? She had less of her endoskeleton exposed than Cromati in the pilot episode.
I believe this series was meant to be a prelude to the new terminator film. People are asking for a third season, but this is the third season. Season 1 was only 9 episodes long. Season 2 has 22 episodes. Season 3 ran back-to-back with season 2 so that it would not clash with the film franchise. The film franchise, which is supposed be a trilogy, will now form a natural, seemless continuation of the terminator saga.