The typography for 'Disney' works because its personality represents the product perfectively. It is bold, curved, with soft fluid movement, and is fun and playful. Just like the Disney cartoons.
The original typography in the logo works well for the 'Gap' Brand, the use of serif and uppercase gives a important feel to it, yet is simple and clear. The brand is for clothing, that is of good quality, basic, casual clothing and essentails.
However the new logo that they unveiled, consisting of Helvetica typeface (a common typeface used amongst graphic designers) was not as effective. This was not just because most people are identifiable with the original logo because it is so well established, but becuase the typeface does not retaint he same personality of the brand. Less to say it was scrapped.