Same here, i am loving it!Personally I like it, took a bit of getting used to but i found that switching back to normal was just awkward with the new swipe animations for going back and forth and switching between spaces.
No they should not since the navigation within the lion is optimized for inverted scrolling, it really is more natural.They should leave the old setting as default.
I was confused at first but it is more intuitive (guess that's why it's called natural). I then changed it back to the old up is down way. I have since decided to try it the new way and changed it back. I'm still confused but determined to give it a couple of days and see if it becomes natural. If not LI'll just go back.I changed it immediately as soon as I installed Lion. Can't stand it inverted.