Notable changes in Wine 1.3.9 include beginning to support Microsoft ActiveX within Wine's built-in web-browser, icons for Internet shortcut menu entries, standardization of code implementing COM interfaces, new scheme for auto-generated DLL registrations, and an OpenCL library wrapper. There's also the usual translation updates and bug-fixes. Approximately 57 bugs have been officially fixed in Wine 1.3.9, which is a bit more than usual for these bi-weekly snapshots.
It's nice to see an OpenCL 1.0 library wrapper for Wine so that Windows applications could still take advantage of this open GPGPU API on Linux, Mac OS X, and other operating systems, but it's perhaps a bit premature. Wine still lacks full Direct3D 10/11 support (nor have they optionally supported the Direct3D 10/11 Gallium3D state tracker) and support for other newer Windows technologies where this GPGPU API standard may be more commonly used in the first place.
There's also the matter of OpenCL support under Linux right now only being in the proprietary NVIDIA and AMD/ATI Catalyst drivers, but not the open-source drivers. There is work towards supporting OpenCL in Mesa/Gallium3D, but that's far from being complete for OpenCL 1.0/1.1 support or even being in a functional state. So right now Wine support for OpenCL will be of limited use, besides the fact that it's just a basic OpenCL 1.0 implementation for now.
The Wine 1.3.9 release announcement can be found at WineHQ.org.