[sigc] Deprecate libsigc++ lambda expressions?

[Kjell Ahlstedt <kjell ahlstedt bredband net>]

Bug https://bugzilla.gnome.org/show_bug.cgi?id=672555 suggests that 
libsigc++ lambda expressions shall be deprecated.
They duplicate the functionality of C++11 lambda expressions. When 
libsigc++ lambda expressions are deprecated, sigc::group() will also be 
deprecated. (The frequently used sigc::mem_fun(), sigc::ptr_fun(), 
sigc::bind(), etc will not be affected.)

Do you use libsigc++ lambda expressions? Any objection to deprecating 
them? Other comments?