http://www.gamebanshee.com/previews/falloutbos.php
The development team seems to understand the intensity of devotion to the Fallout fanbase and is adamant that serious care was taken to ensure that FBOS remains true to the spirit of the original Fallout RPGs and that contradictory information has been avoided at all costs. That said, FBOS does take place at a later time than Fallout, so the developers wanted to give it a look that would reflect the evolution of the culture. This means there will still be a 50s influence to the aesthetic of the universe, but less so than in earlier games.