You mean except for the different versions of the main quest? The side quests? Locations we haven't seen? Characters we don't know about? Who House really is? Everything else that can be spoiled? All the meshes and textures that haven't been shown? Weapons? Armor? Clothing? I make my point.
No, not really.
FNV uses what? 75%-80% of FO3 assets, if not more? There are going to be a few new meshes, and a lot of those are based on the old ones anyway. For example, the "new" NCR uniform, it is the FO3 grunt merc armor with an overcoat. Or the mutants, who do have mod-like tweaks, but not exactly new meshes.
We may not have "seen" all the new locations, but it is not like they are going to be that different from one another, a few more meshes here and a few more textures there. We already know what The Strip looks like, what the inside of the casinos look like, what the Dam looks like, what some of the settlements look like, etc. from the countless demos and review clips, and you can see a lot of FO3 assets in it.
Most of the weapons, if not all, have already been revealed and pictures posted.
All the new creatures have been revealed.
We know who voices the main characters.
We know the main characters.
We know some (if not most/all ) of the secondary characters.
We know exactly how the game starts.
We know what the main quest is.
The side quests? They are all the same: retrieve this, find that, kill him, help her.. and they'll all take you to locations that you already know how they look like, minus whatever new meshes-textures.
.. so, "everything else that can be spoiled" isn't much.