I'm not quite sure, that's probably one for Jackson Rathbone, since his playing the character. But I guess, they might be telling us more in the future movies.

They probably want it to be a big revalation in the next film. That or they are trying to cut it all together, which would be a very bad move on their part.

And, i dont remember good, but...yea i dont think he ever even used his powers in Twilight. an there not mentioned, i guess cuz its only the beggining an everything unravels as the story/movies go on....possibly

i think it will b mentioond in eclipse cos u know about new borns in his past n evrything x

that really irritated me in the movie. that and the fact that jasper didn't even have a last name in the credits.

That annoyed me too >=[
In the film, Edward told Bella that Alice has a power too, that she can see the future. He did not say that Jasper also has one, which annoyed me big time. But, in that scene, when Edward said Alice sees the future, Bella continues talking about Alice and her visions, and how she must have seen Bella coming.. and of course, Alice had seen her, as a vampire, which Edward is not happy about and says 'the future can always change' before getting up. In that scene, I guess there isn't much room for talk of Jasper, and he isn't important. It didn't matter to the plot. So they didn't bother.
However we might - should - find out in another movie - I don't know if it will be New Moon, I think it will more likely be Eclipse, which is kinda late in my opinion... Or, they might not bother with it at all. As though he has no power.
But then, they might have people to answer to.