color normaliztion for an contourf plot

I don't think so; and although I have not thought hard about

    > it, my impression is that adding this capability would take
    > a lot of work and redesign. I expect that in most cases
    > what you describe would not be the desired behavior, so it
    > would have to be a non-default option.

One should be able to write a specific example that exposes this
functionality fairly easily using callback event handling. I'll
provide a simple example using a line plot to get the approximate
ylimits of the data based on the xaxis zoom limits, and maybe some
enterprising developer can extend this example to an image which sets
the clim based on the xlim and ylim

from pylab import nx, figure, show

t = nx.arange(0.0, 2.0, 0.1)
s = nx.sin(2*nx.pi*t)
fig = figure()
ax = fig.add_subplot(111)
ax.plot(t, s)

def on_xlim(ax):
    xmin, xmax = ax.get_xlim()
    imin, imax = nx.searchsorted(t, (xmin, xmax))
    thiss = s[imin:imax]
    ax.set_ylim(min(thiss), max(thiss))

ax.connect('xlim_changed', on_xlim)