I watched the Fallout 3 teaser and it looked alright. The theme and mood seems to at least lean towards the original.
Set for preliminary release in fall 2008 it is a very long wait. I didn't think they would announce it so far in advance. The StarCraft 2 announcement seemed to have a pretty much finished game for instance; so while still possible I doubt there will be over a year's wait for StarCraft 2 to be released.