I've experienced the bug where I killed a coyote with a police baton, which send the beast flying off across the screen.
Also, several bark scorpions stuck in the ground, making for easy pickings. The mountains in the distance also have a penchant for flickering, which is maybe due to my Nvidia card.
What is very positive though, is that there isnt' any frame-skipping so far.
I don't think the atmosphere is better than FO3; if anything, FO3 felt more threatening because it offered complete freedom once you got out of the Vault. NV seems to be more story-driven where a tutorial NPC immediately takes you by the hand and warns you even not to stray too far from the roads.