1) Fallout 3 will disappoint Fallout fans and delight everyone else.
The only thing that confuses me about Bethesda getting the Fallout licence is why they'd even bother. Fallout, while important and brilliant, was never a runaway sales success. At the moment, Bethesda are arguably the most commercially successful western-style Role-playing Game developer on earth. It'd actually be far smarter for them to develop their own post-apocalypse setting from scratch rather than trying to raise Interplay's child from the nuclear ashes.
The idea of Bethesda doing a post-apocalypse game is as big a story as Bethesda doing Fallout 3. Perhaps even a bigger story. Since it'll be presumably be appearing on the consoles, where it'll have no history whatsoever, the "3" is going to make people back away slowly. (Don't
expect it to come out under the name "Fallout 3" but "Fallout: Some Extra Subtitle")
So what have they bought with the licence? Just the enmity of the hardcore Fallout fans who'll hate any game Bethesda make with it just on principle.
So why did they do it? Only reason I can work out is Bethesda are just dirty big Fallout fans and would love to play in the Sandbox. Which is a good a reason for the rest of us to be very excited indeed.