Found this trailer for new vegas looks good http://www.gametrailers.com/video/debut-trailer-fallout-new/61576
Looks really interesting, I heard some good things about it as well. There is some sort of realism option available where you need to eat, ammo has weight and that sort of stuff. Besides with Obsidian at the helm it's bound to be better than FO3 which was a great game already.
Am really looking forward to hardcore mode, also the idea of location specific reputation beyond the normal karma scale is a welcome addition.