The timestamp you're parsing doesn't contain timezone information

#!/usr/bin/perl --
use warnings;
use strict;
use DateTime;
use DateTime::TimeZone;
use DateTime::Format::MySQL;

my @Tzs = ( 'America/Los_Angeles', 'UTC', 'America/New_York',  );
my $somewhere_time = "2011-06-09 08:19:12"; # pacific time?
my $dt = DateTime::Format::MySQL->parse_datetime($somewhere_time);
print $dt->_TZLP;

Tzss( $dt );

print ' ' x 21, DateTime::Format::MySQL->format_datetime($dt),"\n\n";
# I should be expecting to get: 2011-06-09 10:19:12

Tzss( DateTime->now );

sub Tzss {
    my $dt = shift;
    for my $tz ( @Tzs ) {
        $dt->set_time_zone( $tz );
        print $dt->_TZLP;
    }
}
sub DateTime::_TZLP {
    sprintf
        "%-20s %s\n",
        $_[0]->time_zone_long_name,
        $_[0]->strftime("%F %T%z");
}

__END__
floating             2011-06-09 08:19:12+0000
America/Los_Angeles  2011-06-09 08:19:12-0700
UTC                  2011-06-09 15:19:12+0000
America/New_York     2011-06-09 11:19:12-0400
                     2011-06-09 11:19:12

America/Los_Angeles  2011-06-09 09:43:52-0700
UTC                  2011-06-09 16:43:52+0000
America/New_York     2011-06-09 12:43:52-0400
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