The changes in the 2012PV are very compelling, yes. Does it eliminate the need for HDR (or other exposure blending methods)? No. You're still limited to what the sensor in your camera can capture. If you've got a camera like the new Nikon D800 that tests at 14+ stops then your need for exposure blending may be minimised. But if you're shooting with an old Canon 30D that's got maybe 8 stops of range the new raw engine in LR/ACR isn't going to help you get to 10 or 12 or more.