Brain Drain ++

Dr Dan http://it.toolbox.com/blogs/dr-dan/lets-all-play-the-brain-drain-game-24159 here notes about brain drain, the "process" and the act of "capturing knowledge" with a luxury of time.
The real problems in a "typical" software services company where you do not have much future visibility on either people or the knowledge need are
the above plus
a time compression
and key people leaving repeats itself before the close of a contract (not so often if you are a lucky PM)
This is in addition to trying to optimize a firm for the one $$$ variable (reduce costs) when "billability" is given the most priority over all other parameters (suitability, contextual continuity, quality ...) and further brain drain is orchestrated deliberately as well.
Any strategies, suggestions???