Splitting the #__users table name column into 3 columns (first name, middle name and surname) will simplify lot of use cases where you don't want to get the users full real name. Post processing the name will result in a flawed result since you can't predict with 100% accuracy how the name is composed.

E.g. a mail form where you want to address the person "Hi, James \n\n Just for today we have a special offer...".

http://ideas.joomla.org/forums/84261-joomla-idea-pool/suggestions/1241451-name