NA NA!
j/k
I work as character layout (which is like a 
"key frame" animator) for Rough Draft (Futurama 
show) so I know a lil about it. MUAH!

Anyway,  even if the rough drawing were traced in 
the computer, they wouldnt be printed out and 
rescaned, they would just be directly colored. BUt 
anyway, that's not the point.

It would actually take MORE time to trace a 
drawing on the computer, than it would to trace it 
(and clean it up) by hand.  Tracing on the 
computer is actually very labor intensive, and is 
only done if a drawing is to be reused for lots of 
things (and often at various sizes)  If you 
retrace a drawing (or a logo) in a vector based 
program, it can then be shrunk or enlarged to any 
degree without any degradation of the image. This 
is usefull for say logos for businesses, or 
clipart, that kind of thing.

However with animation it is completely 
unnessesary, and well, would be wasting alot of 
time and effort.  The drawings are simply drawn 
clean and then scanned in at the exact resolution 
needed for the field size the "camera" will need. 
There isnt REALLY a camera anymore (except for the 
scanner) since everything is being done in the 
computer.  The animators still do all the 
animation by hand (unless its 3d animation of 
course)  its just that instead of having to take 
the long and sometimes imperfect task of hand 
painting and inking the cels, it can be done in 
the computer. Computer coloring also saves ALOT of 
money (cels and paint are expensive, as is the 
labor used to paint them). and it also allows 
certain compositing effects and coloring effects 
to be done. I'm not saying that computer coloring 
is nessesarily better, certain things can only be 
done by hand.

If you've seen the OLD disney's Fantasia and you 
look at the airbrushing techniques on the fairies, 
you'll know what I'm talking about... the new 
stuff just doesnt have quite the same softness or 
hand done look to it, which I think isnt quite as 
nice even if it is more efficient.

The original animation drawings however will 
ALWAYS be done by hand unless the animation is 3d, 
or they figure out a way for people to draw in the 
computer more easily.

(I dont know if you've ever tried drawing with a 
wacom tablet, but its just NOT the same as drawing 
by hand. also, its usefull to be able to flip the 
paper, something that just isnt the same in the 
computer)