I see them as having two different sets of displayed values. RGB values are easily accessible in CorelDraw while hex values are not. Because many web designers set color values using hex, it would be nice to be able to switch into a color mode which displays color values in hex in order to design graphics using these values.
I can't tell you how many times I've had a programmer call me up asking for hex values for the background of a graphic I created in CorelDraw.
And while "Hex" does appear in the PhotoPaint help file, it does not appear at all in the CorelDraw help file.
It's all a bit surprising to me since hex is a big part of web-related graphics.