I like it.
And to those complaining that robe wearers without shields will get hit harder, well yeah. Expect that to happen sometime, in some form, anyway. People complaining that armors and shields are worthless has been going on for some time. Either they'll get a buff in AC, dps, like the new shield bash thing, DR, or something like this, or some combo.
And, it wouldn't be a nerf to healers. Not really. Making the game a bit harder in general isn't nerfing the healers any more than changing everyone's dps would be a nerf for bards and other buffers. People will have to play a bit smarter to allow their healers to do their thing, and, to me, that's a good thing.