I know I'm getting tiresome ...

my $parser = XML::Rules->new(
  rules => {
    _default => 'content',
    category => 'content array',
    entry => 'array no content',
    post => 'pass no content',
  }
);
my $data = $parser->parse($the_xml);
foreach my $entry (@$data) {
  print "Title: $entry->{title}\nContent: $entry->{content}\n";
  if ($entry->{category)[0] eq 'blog') {
    print "It's a blog post\n\n"; 
  }
  ...
[download]

or

my $parser = XML::Rules->new(
  rules => {
    _default => 'content',
    category => 'content array',
    entry => sub {
      my ($tag,$attr) = @_;
      delete $attr->{_content};
      $attr->{type} = shift(@{$attr->{category}});
      return '@entry' => $attr;
    },
    post => 'pass no content',
  }
);
my $data = $parser->parse($the_xml);
foreach my $entry (@$data) {
  print "Title: $entry->{title}\nContent: $entry->{content}\n";
  if ($entry->{type) eq 'blog') {
    print "It's a blog post with labels: ".join(', ', @{$entry->{categ
+ory}})."\n\n"; 
  }
  ...
[download]

or if you like you can handle each the <entry> within the sub specified in the rules and forget the value then and save memory.