Just received a reply back from John on RadeonPRO forums, to quote:
Newer version of RadeonPro that's still in development already features CPU/RAM monitoring in OSD (CPU clock, load and temperature and RAM usage/total/available) so basic system monitoring will be possible out of the box. However HwINFO provides a plethora of information like GPU VRM temperature monitoring and other data that might be useful for hardcore users.
RTSS shared memory model is public so I guess I could code new RadeonPro to be compatible with RTSS model making it easier for Martin to write HwInfo data into RadeonPro shared memory.
So for anybody running x64 native programs, it is great news to hear as they can have a CPU/RAM/GPU OSD monitoring, at least in a stand-alone app from RadeonPRO v2. For enthusiasts or those that play with voltage it is still lacking unfortunately, in saying that though I'd never replace HWiNFO64 for monitoring the system and am guessing alot of other users would probably feel the same.
I'll have to post another thread on RadeonPRO forums to see just how compatible the app. is with nVidia cards, I did a search for x64 program compatible OSD software and came up blank, other than RadeonPRO which is good for Radeon users.