Descriptive Statistics for Non-Excluded Cases

A small but interesting wrinkle. Many data sets include cases with missing data (hopefully not too many) and these cases will be excluded from many regression specifications. When "describing" the data set, does one use all of the cases (including those cases excluded from regression analyses) or just those cases included in the regression? If it's the latter, is there an easy way to generate basic summary statistics for the non-excluded cases? (The answer to the final question is "yes," and a helpful explanation--and illustrations--can be found here.)