That's probably an expansion path being considered. There are plenty of series that have had big cult success after their cancellation. Firefly is one of them but there's also Arrested Development and, more recently, Better Off Ted for example. Letting others take the risk and capitalizing after proven market viability (basically picking up half of what Fox cancels) could be interesting.
Yeah, the last few episodes of Sarah Connor Chronicles were really exciting. The last episode is a twister, and you really want to know what happens next in the story.
Disclosure: I never saw Terminator 4, so my knowledge of the series is not complete. I'm told that I'm one of the lucky ones, though. :-)
FYI, it supposedly fell somewhere between the T2 & T3 movies in the timeline. Mostly good episodes with the story picking up (and frankly getting crazier in a good way) by the second season.
It's worth a watch if you can handle knowing you won't get all the answers due to its cancellation.
