On closer inspection, I can't find anything official that mentions Taylor at all (other than him looking forward to the Half-naked line, which I think we all are). Wiki says "Taylor
may not be playing Jacob" but wiki is pure speculation, and not a reliable source. It does go on to say that it will be decided by the new direction, which I suspect is the case of anyone who wasn't signed before Catherine left the helm. So I will try not to panic or feel bad for little Taylor yet (who is so like a puppy to me, he just has to play Jacob!!!)
Here's what wiki says (it's on the page about the New Moon book):
After the hugely popular Twilight movie, Summit Entertainment has opted on making a film of the next book in the saga, New Moon. The date has not been exactly set, but it is certain that it will be coming out in the year 2010. Kristen Stewart and Robert Pattinson will be in the movie again, but Taylor Lautner might not be playing Jacob Black. They are still trying to figure out if they can find a better actor, due to Jacob's staggering physical differences he undergoes during the book. They will decide when they hire a new director. It was just noted that director of Twilight, Catherine Hardwicke, will not be directing New Moon.
(emphases mine)