MMO-Champion posted this quote today, which comes from UK PC Gamer article about WotLK:

PC Gamer: What else is changing?
Tom Chilton (Kalgan): We’re also going to be doing away with spell-damage only type gear. We’ll be moving to a system that, as part of your talents, will let players convert healing into spell-damage and vice-versa as part of their talents. That way they can use the exact same gear, but their talents just adapt what it does.”

That pretty much confirms the information leaked from alpha some time ago.

Terhix