[Moved to DR at the October, 2015 meeting.]

Proposed resolution (May, 2015):

Change 13.8.3.2 [temp.dep.type] paragraph 9 as follows:

A type is dependent if it is

• ...

• a simple-template-id in which either the template name is a template parameter or any of the template arguments is a dependent type or an expression that is type-dependent or value-dependent or is a pack expansion, or

Consider an example like:

  template<typename ...Ts> struct X { X(int); };
  template<typename T> using Y = int;
  template<typename ...Ts> void f() {
    X<Y<Ts>...> x;
  }

The presence of the ellipsis should make the reference to X a dependent type, but there is no rule making it so.