If you haven’t already, you should check out this article from Phil Galfond (2+2’s Jman, one of the best NLHE players online) in the latest issue of Bluff magazine. It’s an excellent discussion of how to think in terms of ranges of hands and how mixing up your range can make life hell for an opponent. The one thing that I think he could have made a bit clearer is that you make G-Bucks with ranges, not with particular hands. So it’s not a question of what is a river bet with AA worth in $G-bucks, it’s what is a river bet with {AA, whiffed AK, set, whiffed flush draw}, for example, worth in $G-bucks. The inclusion or exclusion or hands within the range affects the EV of every other hand in the range, which is why you need to consider the range as a whole and not just individual pieces of it.
I’d also like to see more discussion of dynamic ranges and how history, metagame, and table conditions influence these ranges. In my experience, it is not so simple as to say, “X great player has a betting range of 25% AA, 35% set, 40% bluff in this situation”, because his bluff and value-betting frequency will be affected not just by the board and action on previous streets but also by his current table image and how the game has been playing.