'Running out the clock' is a great way to put it, I think. I feel like quite a few shows that kind of toe the line between 'procedural' and 'character-driven' genres tend to do this with their would-be couples. And it never makes any sense. Characters should be put together when it makes sense within the story. Dragging it out until the very last episode of the series isn't going to do anything but bore the audience to death or make them cease caring about the two characters in question because the storytelling has become unrealistic. (Ranting, I know, but this is a big pet peeve of mine). With Bones I started to lose faith after the Zack reveal, but really it was the idea that they were purposefully putting off Booth/Brennan because they were afraid of what would happen if they became a couple- like they wouldn't know where to go from there, or something.

While the pregnancy reveal in Bones didn't disappoint me, it's only because I've had no expectations for this show for a while now. But I definitely see your point about how limiting pregnancy story lines often are for female characters. In HIMYM both actresses (playing Robin and Lily) were pregnant (around the same time) but the show didn't put it in. Robin has never wanted kids, and Lily wasn't specifically trying for one yet with her husband, so it really made sense that the show did this. Now Lily is pregnant, and it makes sense within the story (though admittedly she and her husband trying for kids had some definite cliches thrown in there).

I've never seen IPS, but from the commercials it looked like a decent show, and even from my limited info on it I can say I'd be disappointed with the decision for the main character to have a baby (especially if the actress herself admitted she didn't feel it was right for the character).