Tomonobu Itagaki has been a busy man, ever since he revealed his fan favorite franchise Ninja Gaiden would be seeing an iteration on the DS in Ninja Gaiden: Dragon Sword and a sequel on the Xbox 360. He's conducted lots of interviews about the DS game since then, answering the same question as to why he chose the DS over the PSP over and over again. Aside from the almost God-like status he enjoys in the gaming industry, he's quite the unlucky guy.
Aside from the quote where he says the game is 50% complete, he also comments on one of our concerns about the handheld title: the elaborate and breathtaking environments. Team Ninja is striving to meet those expectations on the portable platform. Not only that, but the handheld's lead programmer was almost single-handedly responsible for the fighting engine in both Dead or Alive 4 and the first Ninja Gaiden.