Is "leadership" a verb or a noun?  I'm not trying to be cute—the real question is whether leaders are simply born, or can be made.

To step back, leadership is one of those ineffable qualities the intrinsic desirability of which no one questions—but which next to no one has been able to define, aside from weak tautological efforts along the lines of "someone people look up to." 

I believe the elusive nature of leadership reflects the reality that it means different things in different situations.  In a crisis, for example, a decisive, directive approach is called for; in calmer times where inspiration needs to be generated, a collaborative and visionary style is needed.

Indeed, the more closely the management literature has looked at leadership, the more diverse its manifestations seem to be.  What, then, can we say about how a firm can cultivate its next generation of leaders?  (I'm assuming the incumbents are, well, the incumbents.)  Managing Partner magazine helps distill the roadmap:

• Create a vision.  This means capturing the hearts and minds of people with a call to action to engage them in creating the firm's future.  Financial analytics and market assessments are surely part of this process—to ensure the business case is sound the promised land realistic and attainable—but engaging people's emotional juices is your primary challenge.  The rationale, truth be told, comes later.
• Walk the talk.  Even as young children—perhaps especially as young children—people's hypocrisy detection sniffers are as powerful as a dog's nose.  If your proclaimed goal is to institutionalize the client base and promote collaboration and professional development, for example, you'd best be seen as acting that way yourself.
• Face hard realities.  The reason you call it a "vision" is that it's not yet reality.  In other words, there's a gap between where we are and where we want to be.  Do not duck, temporize, or change the subject.  If people's behaviors have to change, a steady diet of comfort and reassurance isn't going to do it.
• Breed cohesion.  Griping, splintering, and conflict must be avoided or faced squarely and dealt with.  How?  Withholding judgment until all (well, all rational) points of view have been heard; enlisting cooperation and avoiding the Lone Ranger temptation.  Explaining fully to those whose opinions were on the losing side how you reached your decision.  And once the decision has been made, it's time for folks to get on board.  (Yes, the recalcitrant may have to be made an example of.)  And lastly:
• Celebrating wins.  Reward progress.  Recognize individual contributions.  Point out the distance traveled.

Assuming you concur that this all sounds beneficent, how can you get there from here?

Fortunately, the management literature, again, has something to say.

• Developing leaders needs to permeate the firm.  This means it should change the way you recruit, change your coaching and professional development efforts, and change your retention and promotion criteria.  Remember "walk the talk?"  Here it is in action.
• Expand training beyond "skills" and into "behavior."  A technical capability can be developed through essentially cognitive tools, but a set of attitudes and behaviors are complex and require time, feedback, nuanced coaching, and an unusual degree of self-awareness on behalf of the lawyers being groomed for leadership.  This takes planning, commitment, dedication, and follow-through—activities and behavior patterns to which lawyers are no strangers.

Now, the reaction of many lawyers to a conscious, premeditated plan to develop the next generation of their firm's leaders through reliance on tools born in behavioral science and honed in corporate America may be the reflexive, "But we're different than a corporation!  What other law firm does that?  We've always let partners develop autonomously."

The answers to which, in order are:  (a) less different than you think; and why not adopt proven techniques that the F500 and their brethren have learned often at the cost of paying great tribute to McKinsey & Co.;  (b)  perhaps few—and so?; and (c) is your track record under the autonomous model the equivalent of a best-of-breed executive development environment (say, GE)?

The need for leadership is real, as are the tools to address it.  It's too late to pretend the best we can do is letting nature take its course.