I have a pair of last years and this years stealths sitting next to me, and this years are improved by 110%. and to me i notice just by holding them in my hand: thicker core profile, different core design, new topsheet (coating), better edge design, stiffer ovrall flex, and new tip and tail shapes really round and blunt. (and light as hell)
And the website isn't up yet, but when it is im sure it'll explain everything you want to know.