Actually, more than enough information exists in the gameplay videos pointing to the fact that FO3 will be guaranteed to be an absolute piece of shit.
It is a hybrid FPS/RPG that will be completely unsatisfying for people who like either or both genres. The RPG part is, so far, nonexistent. The hacking minigame looks as annoying as Oblivion's persuasion wheel. The only thing we know about dialogues is that they have been avoided at all costs in the previews, and that the guy from WIRED said they could be compared to fan-fiction material. Regarding the FPS part, non-VATS firefights appear to be nothing but dull exchanges of fire against opponents that score negative numbers on their I.Q. tests. Weapons do not look attractive and appear to have no "feel" to them at all. Combat will most likely be extremely difficult, if not impossibly so, without the constant use of VATS, which gets old immediately (unlike the Bloody Mess physics for the Toddler).
The only thing Bethesda seems to have imitated from the previous Fallout games are the aesthetics, and even so it was done in a crude and tacked-on fashion. Furthermore, any features shown in the previews are not fully guaranteed to be true or to work exactly as described, as it may be nothing but bait-and-switch material as was the case with many of the features shown in the Oblivion previews.
It is clearly evident that, at best, FO3 will be precisely Oblivion With Guns and VATS. But no matter how tasteless and horrible this concept is, many people will like it, praise it, and recommend it. It might be easily forgotten later on, but it will have sold enough to make it a commercial success, and will serve as a shining example for other companies in the video game industry to imitate.