(Use the poll at the top so we can see if this really is a true fix)

I just got FO:NV on steam for Christmas and could not get through this non-responsive black screen.
I know a lot of us are having issues with this so try this out if you have a steam copy.

Open the properties by right clicking on the game in the game library.
Go to the Local Files tab and Click Verify Integrity of Game Cache
Steam will display a progress bar for about 10 minutes and tell you that a file is missing.
FO:NV will then download the file through steam.

After this the game should start fine and you will be able to play.

I hope this helps for you all as it has for me.

Now if I could find a fix for the random crashing...