OS X never[1] seems to require more than 8 GB, no matter how many applications you have running - I've got 28 right now, including the Office Apps. Google Earth, Various Browsers, etc... and system is ticking along nicely. I've got to believe that is a testimony to the power of shared libraries.
[1] Yes, I'm aware there is an infinite range of work loads (Video, Audio, PhotoShop, Virtualization, Oracle, etc.. that can use up as much memory as you throw at it - I'm talking about the joe average user workloads here
[1] Yes, I'm aware there is an infinite range of work loads (Video, Audio, PhotoShop, Virtualization, Oracle, etc.. that can use up as much memory as you throw at it - I'm talking about the joe average user workloads here