re no root for android L be aware chain fire from XDa is working on the root mechanism for Android l

So far for those who have rooted devices be aware if you flash the
Android l preview build you will lose root and at this point of the game
none of these root kits have a root mechanism available since Android L is
using ART and not delvic which is going to bea a challenge for rooted
application as well as rooted devices. So for the time being if you have a
rooted device be aware that the Android l preview build will break root and
there is no mechanism at this time that will gain root back. So for the time
being there are few XDA well known developers Chain fire and GHud who are
working on mechanisms to root the android l builds.