Have you looked at:
http://smartwin.sourceforge.net/
I have never tried it (if I did Windows GUIs I would check it out) so I cannot vouch for it, but it sounds interesting:
"SmartWin++ is a modern designed C++ library, it uses STL where possible and boost where needed..."
"...We believe that STL and Boost are good tools and should be used in favor of creating your own bug-prone classes to substitute them! If it exists in Boost or in STL it does NOT exist in SmartWin++!! :)..."
"... SmartWin++ does NOT try to solve your marriage problems. It cares only about GUI. If you need a network library, search elsewhere. SmartWin++ will not solve your TCP/IP problems or your HTTP problems or your Dijkstra's Extra problems! SmartWin++ is about GUI, nothing more, nothing less! We try to be the best in ONE area which is GUI development! This makes the library small, slick, fast and good looking! ;)"
-- Michael
It looks like this library hasn't been worked on in nearly 2 years.