If you do away with the conditionals like that, the temporaries in the while loop are superfluous.

my ( @arr0, @arr1 );

while( @array > 1 ) {
    push @arr0, shift @array;
    push @arr1, shift @array;
}
push @arr0, shift @array if @array;
[download]

Or you could pull the conditional back into the loop:

my ( @arr0, @arr1 );

while( @array ) {
    push @arr0, shift @array;
    push @arr1, shift @array if @array;
}
[download]