Aggregates with NaN values

I am happy to see NaN and infinity handled in input.  I would now like
to compute aggregates (avg, min, max, etc) on columns with NaN values
in them.  The standard behavior (it appears) is to have the aggregate
return NaN if the data contain one-or-more NaN values.  I am used to
using coalesce with NULL values, but that doesn't work with NaN.  I
can deal with these using CASE statuement to assign a value, but is
there a standard way of dealing with the NaN (or Infinity, for that
matter) cases to get a behvavior where they are "ignored" by an
aggregate?

Thanks,
Sean