unnest on multi-dimensional arrays

It appears that unnest, when called on a multi-dimensional array,
effectively flattens the array first.  For example:

=> select * from unnest(array[array[1, 2], array[2, 3]]);
  unnest
--------
       1
       2
       2
       3
(4 rows)

while I would have expect something like the following:

=> select * from unnest(array[array[1, 2], array[2, 3]]);
  unnest
--------
    {1, 2}
    {2, 3}
(2 rows)

Is there any way to get the latter behavior?


Zev