How much more useful are ever higher pixel densities?

I came from the lower MP olympus models and haven't been shooting with my D7000 for that long. One thing I have discovered though is that to get full use of the extra resolution, I have to use insanely good technique, i.e. heavy tripod, mirror lockup with remote release or use very high shutter speeds etc. The shots at lower speeds and using VR while "acceptable" and do make nice 8X10 prints aren't something pixel peepers would drool over. I know many of the D800E owners have discovered this too.

I guess I'm starting to wonder: is an even higher pixel density going to be even worse about technique, quality of the optics etc to get anything more than the current density provides? My though is, for most people who are hand holding in lower light levels using moderate shutter speeds, will it really be much if any improvement. As I have found in many things in life, what is shown in labs sometimes doesn't pan out in real world use.

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Stacey