表題のモジュールを書きました。
うそ、パクりました。にぽたん研究所から。

先に使い方から説明すると、まず「http://api.del.icio.us/v1/posts/all?」ここにアクセスすると、自分が今までにdel.icio.usへポストしたブックマークをすべて取得できるので、それを取得しておきます。ベーシック認証がありますが、それは自分のdel.icio.usのアカウントを入力してください。

次に下記のスクリプトを用意して、先程del.icio.usから取得したブックマークのデータ(all.xmlというファイル名にしておいてください)と同じディレクトリに置いたら、あとはスクリプトを実行するだけです。もちろんあとで紹介するWWW::SyncSBS::D2Lも用意する必要があります。 
#!/usr/local/bin/perl

use strict;
use WWW::SyncSBS::D2L;

my $d2l = WWW::SyncSBS::D2L->new;
$d2l->livedoor_id('your_ld_id');
$d2l->livedoor_pw('your_ld_pw');
$d2l->sync;
WWW::SyncSBS::D2Lの本体は↓です。 
package WWW::SyncSBS::D2L;

use strict;
use Carp;
use HTML::Entities ();
use WWW::Mechanize;
use URI;
use XML::Simple;
use base qw(Class::Accessor::Fast);
use Encode;

__PACKAGE__->mk_accessors(qw(mech livedoor_id livedoor_pw debug));

sub new {
    my($class, $args) = @_;
    my $self = bless {
        debug => 0,
    }, $class;
    if ($args && ref($args) eq 'HASH') {
        for my $method (keys %$args) {
            if ($class->can($method)) {
                $class->$method($args->{$method});
            }
        }
    }
    return $self->_init;
}

sub sync {
    my $self = shift;
    $self->login_livedoor_clip unless $self->{_logged_in};
    my $posted = $self->parse_delicious_bookmark;
    $self->clip_to_livedoor($posted);
}

sub login_livedoor_clip {
    my $self = shift;
    unless ($self->livedoor_id && $self->livedoor_pw) {
        croak('set your livedoor_id and livedoor_pw before login.');
    }
    unless ($self->_has_clip_account) {
        croak('register to livedoor clip before using this module.');
    }
    my $res = $self->mech->get('http://clip.livedoor.com/register/');
    $self->mech->submit_form(
        form_name => 'loginForm',
        fields => {
            livedoor_id => $self->livedoor_id,
            password    => $self->livedoor_pw,
        },
    );
    # XXX login checking (WWW::Mechanize->uri() doesn't work correct).
    $self->mech->get('http://clip.livedoor.com/register/');
    $self->{_logged_in} =
        $self->mech->uri =~ m{^http://clip\.livedoor\.com/} ? 1 : 0;
    unless ($self->{_logged_in}) {
        croak("failed to login to livedoor clip.");
    }
}

sub _has_clip_account {
    my $self = shift;
    my $myclip_url =
        sprintf('http://clip.livedoor.com/clips/%s', $self->livedoor_id);
    my $res = $self->mech->get($myclip_url);
    return $res->is_success ? 1 : 0;
}

sub _init {
    my $self = shift;
    unless ($self->mech) {
        my $mech = WWW::Mechanize->new;
        $mech->agent_alias('Windows IE 6');
        $self->mech($mech);
    }
    if ($self->livedoor_id && $self->livedoor_pw) {
        $self->mech->login_livedoor_clip;
    }
    return $self;
}

sub parse_delicious_bookmark {
    my $self = shift;
    my $feed = $self->_get_content();
    my @posted = $self->_parse_feed($feed);
    return \@posted;
}

# XXX parse using regexp
sub _parse_feed {
    my($self, $feed) = @_;
    my @posted_data = ();
    my $xml = XMLin($feed);
    for my $post (@{$xml->{post}}) {
        my $title    = $post->{description};
        my $url      = $post->{href};
        my $summary  = $post->{extended};
        my @tags = $post->{tag} eq 'system:unfiled' ? () : split(/ /, encode('utf8', $post->{tag}));
        my $data = {
            title   => encode('utf8', $title)   || '',
            url     => encode('utf8', $url)     || '',
            summary => encode('utf8', $summary) || '',
            tags    => \@tags,
        };
        push @posted_data, $data;
    }
    return @posted_data;
}

sub get_bookmark_count {
    my($self, $feed) = @_;
    my $count;
    if ($feed =~ m{(\d+)};
        unless ($count) {
            $count = scalar($feed =~ m{(.+?)}sg);
        }
    }
    return ($count || 0);
}

sub _get_content {
    open(FH, "all.xml");
    my $f = join('', );
    close(FH);
    return $f;
}

sub clip_to_livedoor {
    my($self, $data) = @_;
    for my $posted (@$data) {
        my $uri = URI->new('http://clip.livedoor.com/clip/add');
        $uri->query_form(
            link  => $posted->{url},
            jump  => 'page',
            tags  => join(' ', @{$posted->{tags}}),
            title => $posted->{title},
            notes => $posted->{summary},
        );
        my $add_url = $uri->as_string;
        my $res = eval { $self->mech->get($add_url) };
        if ($res && $res->is_success) {
            eval { $self->mech->submit_form(form_name => 'clip') };
            if ($@) {
                carp("can't submit: " . $posted->{url});
            }
        }
        else {
            carp("fail to clip $add_url HTTP Status: " . $res->code);
        }
    }
}

1;