And that end result is complete different from your solution.

Hmm, don't know how I managed to mess that up. Oh well, here's the reverse:

use strict;
use warnings;

my $raw = '<P_contrib-author>Allan Wigfield, Susan L. Klauda, and Jenn
+a Cambria</P_contrib-author>';

$raw =~ s/<P_contrib-author>|<\/P_contrib-author>//g;

print "<contrib-group>\n";
for (split /, (?:and )?/, $raw) {
    m/(.*) (.*)/;
    print "<name><surname>$2</surname><given-names>$1</given-names></n
+ame>\n";

}
print "</contrib-group>";
[download]

Lots of good ideas, though split can be a dog with large volumes of data, like a book written at a frat party. I can't think of how to do it without using a match to follow, but a nice 2am ugly regex can do it all(tags have been pre-stripped):

$_ = "Allan Wigfield, Susan L. Klauda, and Jenna Cambria";

   while( s/^(\w+(?:\s+\w\.)?)\s+(\w+)(?:,\s+(?:and\s+)?)// )
     { print "First Name: $1\nLast Name: $2\n";}

It's ugly, but it works.