Absolutely, the post-*crement operators MUST create an anonymous value, so they do.

I wonder though, what the "expected" or "natural" behavior of the other constructs I posted should be.

Construct  Behavior  Expected
$i += 2    \$i       ???
$i++       Anon.     Anon.
$i + 1     Anon.     Anon.
$i++       Anon.     Anon.
++$i       \$i       Anon.
$i=2       \$i       ???
[download]

From reading the other posts here, I feel comfortable saying that people expect ++$i to pass an anonymous value. I'm not 100% sure what I'd expect the assignment operators (=, *=, etc) to pass. Since most langauges pass by value, I guess I'd expect the assignment operators to pass anonymous values equal to the value assigned to $i. For example for foo($i=2) my faulty intuition is that foo() would get an anonymous 2 in $_[0].