Developer 2D Boy makes the popular World of Goo game, which they recently released on the iPad, and the official blog has a long writeup about the iPad version from creation to release. 2D Boy originally planned to release the game on the iPhone, but couldn't get it to work right, so when the iPad came around, they decided to tackle the port again. The writeup outlines not only development of the game, but also marketing (after an early choice to release at US$10, they eventually lowered the price to pick up some sales boosts) and even the timing of their release -- they landed right in that "loophole" around Christmas that allowed them to pick up some extra sales by being on the charts during the App Store freeze.
And perhaps most interesting is 2D Boy's comparison of the iPad market to their past console and PC experience. The iPad version was the fastest-selling of all of the versions of the game so far, both in copies sold and revenue generated. That's pretty wild, and it shows that not only does iOS offer a lot to developers in terms of when and how they can release their games, but that Apple's platforms stack up favorably to more established marketplaces like WiiWare and Xbox Live Arcade.
Of course, this was the latest version of the game, so it benefited from all of the good reviews and good will from the previous releases. Not all of that credit can go to the iPad itself. As 2D Boy says, in this case, there was a two-year-old game being sold on a platform less than a year old, so there's lots and lots of potential here for indie developers to discover.