Nested statement modifiers (e.g. EXPR1 if EXPR2 for LIST instead of EXPR2 and EXPR1 for LIST)

That is not going to happen: the idea was firmly rejected by $Larry when it was suggested for Perl 6. Although occasionally I've cherished the idea, it's "kinda too much" for me too.

Method names given as expressions ($foo->do{ EXPR }(LIST) instead of my $tmp=EXPR; $foo->$tmp(LIST) or $foo->${\(EXPR)}(LIST))

While I desired that too, but I can't think of a syntax that would be unambiguous:

• $foo->do{ EXPR }(LIST) could be a regular method call. And do is already a (overloaded) keyword. What if one has a do() method?
• $foo->{ EXPR }(LIST) could be a hash dereference;
• $foo->( EXPR )(LIST) could be a sub dereference. And that ")(" is, well, ugly.

Attributes on packages (allowing e.g. package Foo:extends("Bar"))

Well, this would be cool. Wait! I still have to learn how to use attributes on subs... Oh well!!