I agree with the wealth of opinion here in that it would be might hard to get me to 'love' the characters in the game at all. I believe I understand what they're after with this, really, but in the long run, they were after a lot of the same things with both Fable and TLC, and fell short on both accounts. As several have pointed out, there is no lasting repercussion for anything you do in the game, good or bad. The interviews and press releases seem to indicate they're going to fix that with Fable 2, and I sincerely hope they do, because without repercussion there is no accountability, and without accountability, there is no emotional involvement.
One thing I did enjoy in Fable was the subtle pointers to the Ultima series, which were spearheaded by another man who wanted to do everything he could to immerse the players emotions in the game, not just their lustful alter egos. (As an aside, I purchased the Avatar title as soon as I discovered it was available simply because Ultima 5 is STILL my favorite RPG of all time.) The middle three Ultimas(4, 5, and 6) did a very good job of involving the player and getting them concerned about the welfare of the characters, but the later games fell into the 'we have to make it pretty, not involving' trap, which left the me, and others I've talked to, feeling... disappointed and kind of empty at the end. Like, "that was it?" No grand sense of accomplishment, no excitement for replay, no nothing. That's essentially how I felt at the end of Fable as well. "That's it?" Of course, I didn't find out until later (on this forum, actually), that if you let the credits run, you can keep playing. I was thrilled to find out about TLC, and promptly purchased a copy as soon as I could. The game feels much fuller and more realistic than the original, but there is still that void in regards to consequences for your actions.
So even though a companion dog and the possibility of kids present some interesting opportunities to involve the player emotionally, I seriously doubt they will achieve even a modicum of the 'love' aspect they're aspiring to. I can care about a character, even be emotionally upset when something bad happens to them (I'm not ashamed to admit I've cried at movies, books, and even the very rare RPG), but once the book closes or the credits roll, I move the heck on. I do wonder, though, if, when playing as a female character who is pregnant, the combat abilities, et. al. will be affected by the pregnancy, or if the pregnancy will be another one of those poorly executed extras like sleeping with your spouse? Screen turns black and out pops the kid?
Origin Systems created worlds that were emotionally involving and taxing, and so far, only the Elder Scrolls folks have really come close (and in some cases, surpassed) what Origin started. Fable, in retrospect and by comparison, really came off as an 'also ran', you know? Great game, and highly enjoyable, but not the kind of game I'll have long conversations about or spend lazy afternoons wishing to visit. (I would STILL like to visit Buccaneer's Den.) The bar is irrevocably cast high, and for them to reach it, they're really going to have to invest in far more than just making it look pretty. And kicking chickens. It'll take more than that, too.
But then, that's just my opinion... I could be wrong.