Wine 1.4-rc5 was released on Friday with more bug-fixes. With their Git code-base being in a code-freeze for this first official release in two years, there aren't any changes in this version besides bug-fixes. These 1.4 release candidates have been coming out weekly since the code freeze. The announcement can be found on WineHQ.org.
For reference, there were seven release candidates of Wine 1.2 before that release came out in 2010. The indications are so far that Wine 1.4 will be ready for release in March.
To read about the Wine 1.4 improvements and features, see this Phoronix article. There's improved DirectX support, DOSBox integration, X Input 2 support, web improvements, the DIB engine implementation, and much more.