In no way, shape or form should they change the design. For me, it's the only heavyweight title thats looked like a heavyweight title. None of the WWF/WWE titles, as cool as they may have looked, ever gave any type of importance off if I'm being completely honest. I'm not keen on ROH's, and I haven't liked any of TNA's since they lost the NWA belt. The World Heavyweight Championship is different, because it looks very official. It's simple, just gold with no flashy colours on it, hasn't got any clever designs or gimmicks, and it has the nameplate, which I believe it had as the WCW title, and was the belt that first introduced nameplates into the WWE.
As belts go, it's an icon of the industry, and should never be tampered with (excluding the strap and resizing the plates). The design itself should never be changed, in my opinion, and I seriously doubt you'll find many people who think otherwise.