Adding to post from stevieb. There is nothing special about bless vs any other built in function.

Here are some examples using print, to show the quoting ability before the =>

#!/usr/bin/perl
use strict;
use warnings;

print "abc" => "xyz\n"; #prints abcxyz
print abc => "xyz\n";   #prints abcxyz
print "abc", "xyz\n";   #prints abcxyz (most natural formulation)
#print abc, "xyz\n";    #prints No comma allowed after filehandle at C
+:\Projects_Perl\testing\junk1.pl line 7.
[download]

I personally would highly recommend against using => where a comma "," is meant (i.e. your bless statement). And I would also highly recommend its use when defining elements of a hash or calling a function that expects a hash (occurs often in GUI code, -width => 5.0)

update: When I see =>, I think hash, even if I do the double quoting on the left side explictly, e.g. "key with embedded space" => 32