Yes. Its dev time is an appropriate length.
Wind Waker and Twilight Princess both took about 3 years to make, and after finishing Skyward Sword, I recall someone (Aonuma? Iwata? Don't remember.) saying this was their target dev time for Zelda games. Skyward Sword was known to have been in development hell for a couple of years, and wound up taking 5 years to make.
A 2015 release already accounts for a one-year 'delay' to compensate for the team's unfamiliarity with HD platforms. Aonuma has shown a much more focused idea of what he wants this game to be than he had for the first couple of years of Skyward Sword development. This new game did not have those problems.
Basically, it's coming in 2015 because if it had the same problems as Skyward Sword, it would be coming in 2017 and Nintendo wouldn't even have mentioned it yet.
