Firstly, let’s look at the “Computer Animation” featurette. The first thing to understand is why Disney, in the early 1990s felt the need to integrate computer animation into a traditionally animated film in the first place.
While it would be nice to think it was done to relieve the animators of the boredom of having to animate hundreds of similar characters it wasn’t. The reason and the only reason was to save money. As shown in that brief featurette, the CGI wilder beast were, in effect cleaned-up, inked and coloured by the computer. Thus, mainly time was saved, and time equals money.
Now, also looking at the finished film, they did a fantastic job in integrating CGI into the movie and making it look hand drawn. If it wasn’t pointed out, you would never know. And that was with technology 10 years or so old.
Disney are happy to make CGI films that look CGI – mainly because such films haven’t really failed in the past. But they also want to make CGI films that emulate the look and feel of hand drawn animation. That way they get the same result (in their minds) with the fraction of the manpower – therefore a fraction of the cost. Based on their 10 year old example I would guess Disney may be able (or almost able) to pull this off on original characters. I think it will be harder to make existing, established in 2D characters work using this method.
Secondly, the Cyber Zuzu on the disc 1 menu. Now I don’t know for sure, but after finding out that there’s a Lion King segment in the new all-CGI “Mickey's Philharmagic” attraction, I would guess Zazu (and the backgrounds?) are models created for Philharmagic. This demonstrates another appeal of CGI over traditional hand drawn animation – reuse. All of the assets created for a CGI film can be pulled from storage and reused in other projects. Not something that can be done easily with hand drawn animation.
I think the success of failure of Brother Bear will have little (if any) effect on the slow decline of hand drawn animation. Should it be a success it won’t convince Disney to abandon their CGI plans – at the best it may delay them a few years. But all Disney executives will think is how much more money they could of made had the film been CGI with a hand drawn look and feel. Success for Brother Bear and Home on the Range will not generate a huge change of direction at Disney HQ.
Don’t get me wrong, I’m not all for this trend. But from a business point of view – assuming the technology can deliver it sounds like the only thing to do.

We also shouldn’t dismiss CGI films outright. As Pixar has shown, animation skill in CGI is just as important and creative as in traditional animation.