Since pants are usually 1-2" too long for me I never noticed the length changes! I actually bought two petite jeans this year and they are a LOT shorter than the regulars holy moly! Rises are a little too short but it was getting impossible to find something that would otherwise fit without needing loads of alterations (shorten, waist darts, knee break raise, and some shape slimming on some *sigh*). Do the knee breaks move up too with smaller sizes? That's my biggest issue, too low in regulars.
EDIT: Hmm now that I think about it more pants lengths fit better at my current size. I'd just assumed it was because of all the cropped lengths around! Must also be the small size. (Sorry to hijack your thread, Brie!)