tye has written a tool that should serve your purpose. Have a look at mapcar

use mapcar;

my @matrix = (
   [ qw(ab cd ef gh)],
   [ qw(ij kl mn op)],
   [ qw(qr st uv wx)]
);

my @transposed = mapcar {[@_]} @matrix;

print join( "  ", @$_), $/ for @transposed;

__END__
ab  ij  qr
cd  kl  st
ef  mn  uv
gh  op  wx
[download]

Update
mapcar is now a function in tye's Algorithm::Loops.

The above example would becpme:

 
use Algorithm::Loops qw(MapCar);

my @matrix = (
   [ qw(ab cd ef gh)],
   [ qw(ij kl mn op)],
   [ qw(qr st uv wx)]
);

my @transposed = MapCar {[@_]} @matrix;

print join( "  ", @$_), $/ for @transposed;
[download]

With exactly the same result.