$ perl -le'
my @array = (1, 2, 3, 4, 5, 6, 7, 8);
my @new_array = map{ [$array[2 * $_ - 1], $array[2 * $_]] } 1 .. @arra
+y/2;
use Data::Dumper; print Dumper \@new_array;
'
$VAR1 = [
          [
            2,
            3
          ],
          [
            4,
            5
          ],
          [
            6,
            7
          ],
          [
            8,
            undef
          ]
        ];
[download]

This appears to work better:

$ perl -le'
my @array = 1 .. 8;                  
my @new_array = map [ @array[ 2 * $_ - 2, 2 * $_ - 1 ] ], 1 .. @array 
+/ 2;
use Data::Dumper; print Dumper \@new_array;
'
$VAR1 = [
          [
            1,
            2
          ],
          [
            3,
            4
          ],
          [
            5,
            6
          ],
          [
            7,
            8
          ]
        ];
[download]