I'm coming at this not really having followed all the posts, maybe the last few pages. I heard Other M mentioned a page back, and it scared the crap out of me... I don't think any other game has ground a series to a screeching halt to the extent that Other M did. However, I think Lightning has a bit more possible flexibility than Samus, and she's a slightly problematic character to begin with. Samus has always been generic super hero badass, the series never made an attempt to establish her as anything more than a paper cutout, and that's fine for what it is. Other M not only broke with that in trying to develop Samus (which I have no problem with), but basically blew apart everything we had established with her up until then. Instead of being a game where you were able to see a bit more of the subtleties of her character, it re-wrote her character and told us that this is how she should be viewed in every game. horrible.
But this is different. If we take what the designers are saying seriously, they're not trying to re-write her character but develop it. And lets face it, Lightning is pretty gosh darn wooden, and could use some fleshing out. The reason she's so wooden is that they've been trying to push the "ultimate badass" image, which has no depth and every facet is specifically designed to look "cool". But alternatively, we've seen very little of her. We've seen her through one relentless event in which the emotional pathos itself was very unwavering, and did little to test her character. If they continued exactly on the trend they've done up until now, many of us would write Lightning off as bland and boring. We can coolly except that the events of FFXIII-1 were all very static and thus it's not out of the realm of possibility to not see many sides of the character, but it would be a total taste of faith to do it again.
And so where do we go from here? Well, Lightning is about as invulnerable as they come, the only direction is down. Want to see a different side of Claire? (I certainly do) we're gonna have to see her at a slightly more vulnerable state. And as far as I can tell, an "invulnerable" Lightning is probably just a "normal" anyone else, so I doubt we're going to see her fainting or running away and crying in fear. There is no question that they could totally fuck it up, too, that they are playing to the lowest common denominator of female stereotypes and fanservice, but I haven't seen anything to support this or to debunk it either.
The videos I've seen don't really seem all the different, and once again we get the over-the-top "badass" sword poses from the wooden years, so I'm not even sure I believe the change will be noticeable. If done correctly, the vulnerability change could be EXACTLY what Lightning (and the series) needs. Then again, it could be a disaster.
And the outfits... meh. So far they all tend to conform to the "badass" class in different ways. Some of them are ugly, some are interesting, but I'm not feeling bothered by any.
EDIT: on another note, I just watched the new locations vids and I was surprisingly impressed. Many of them FELT different, somehow, than most other games I've played. Especially the Wildlands... there's something very ungeneric about such a typically generic theme. For one, it feels like subarctic wilderness for a change, instead of subtropical. I got a distinct Eastern Washington or rural Canada vibe from it. Also, for the first time since FF8, I think they NAILED the modern day feel in Luxurion, even if it was a bit gothic. Ever since FF9, they've been so intent on establishing that "this is not our world", it's good to see some locales that really feel earth-like again. FFXII had its moments, but they were very limited and generic.