The story of Fallout 3 is not directly connected to the previous Fallout titles. Building from the history and lore of the Fallout world, the game will provide a whole new story, art direction and gameplay. Todd Howard, Executive Producer of the project, has stressed that ‘reinvention’ is a key point in the development of Fallout 3. This is not to say that history and lore will be ignored, but the game play itself will be redefined into a whole new playing experience to separate it from previous titles.
General gameplay aspects are expected to be epic and will reflect Fallout 1 in many respects. One can expect to see high levels of violence and destruction through the Capital Waste. A headshot won’t simply be a shot in the head. It will be a head obliteration. Disintegration, Jellification, Incineration, all manner of gruesome and extremely painful ways to kill or be killed with threaten every step through the massive environment of the ruined DC. Using an evolved version of the same engine used in Oblivion, Fallout 3 is easily the prettiest post-apocalyptic Washington DC any of us have had the pleasure of seeing, let alone run around in.
Now onto the previous Fallout games, if you know Polish than head to Gram.pl, the CDprojekt portal, where you can see the second part of a Fallout history article (with some screw ups on captions). The first part can be found here, thanks for the tip Ausir.