I like brief too ... why not simply:?

my @array2 = map { s/\s+//g; $_ } @array1;
[download]

Update  Whoops, now I see ... it's because you'd be changing the original array.  Still, I like the brevity of something like:

my @array2 = map { (my $x = $_) =~ s/\s+//g; $x } @array1;
[download]