This is a great fix!!! Thank God this is happening!!
What is all this crap about mana? First off... as some people have said, destruction is dependent on gear. With the t7 4 set bonus to life tap, life tap isn't a dps decrease but an increase, and should be up all the time and made part of the rotation. Also there are many people that find soul leech bad talents, but that is also a joke. If your gonna life tap make a macro letting your healers know. With soul leech you will be topped out on health most of the time.
Most everything we know about destruction has changed. Time to rethink things.