axes.pie() creates a number of patches and text instances, but allows a limited subset of arguments in it's call signature.

It would be far more useful if it supported a kwargs argument, where the keyword arguments would be passed on to patch calls.

This would allow a gid to be set, encompassing each patch in the piechart (makes it much easier to then retrieve the handle to all elements of the pie chart for example, or include the pie chart)
Pickers could be set, edgecolor could be easily customised etc..