DeWALT released some new videos today of some new features on their large angle grinders. The first is the dust ejection system. Basically it keeps debris and dust from contacting the motor as it passes across. The particles are diverted away from the motor thus giving you 2X more motor life and a better running tool.
The second is the E-Clutch, it stops the tool when wheel pinch is detected. This saves the tool from inadvertently catching and getting thrown out of the users hand which could be a dangerous scenario. Looks like the DWE4597, DWE4597N and the DWE4599N will have this feature.