I played the demo too (on the 360 for about an hour while everyone waited in the T-shirt or brink line) and I thought that it was pretty good, though it could have used a bit more fast paced action if it was supposed to be a 15 minute demo.
My random thoughts:
I never really paid much attention to the faces of the NPCs other than the female doctor with the spiked mohawk(I guess that's what makes her a "follower"). The NPC faces didn't always move (primarily said doctor) when they talked but I'm guessing its a bug.
That area that the OP went into is still part of Freeside, the "demonstrator" I'm guessing had gotten tired of people trying to kill everyone while saying "I can't kill everything this game must be broken."
The oddest thing I noticed was that I played through the whole demo without firing a shot. Not really a problem, but a bit surprising compared to Fallout 3. I have to have a good ole :gun: every now and then so I looked down the sights of the .22 LR SMG. They need to be opened up a bit because you can't see anything through them.
I like that they added the numbers for what level of speech/science/whatever you needed for the checks. It may seem "ezmode" but its better than stumbling around blind.
It struck me as odd that the NCR troops in town were wearing random merc clothes rather than any sort of military uniform, but i guess they were under cover or something.
The robobrain dog Rex gave me a chuckle.
I also had a good laugh at everyone trying to go on a massacre with the default equipped varmint rifle while failing miserably, especially when attacking guards with plasma rifles

. I do wish that there weren't so many wimpy weapons in the game, but if you don't have as early of access to good weapons that may be a difference.