Most notable to Wine 1.9.5 is that it has the beginning of the long talked about Direct3D command stream improvements for offering better performance of games on Wine. The patches have been in the works for over two years while the work was stalled over waiting on Wine's Direct3D 10/11 work, which continues to be ongoing. It looks like the Wine 1.9 development series leading up to the Wine 1.10 release later this year will finally have the D3D command stream work for offering faster Windows gaming performance on Linux.
Wine 1.9.5 also has a new version of the .NET Mono engine with 64-bit support, support for effect states in Direct3DX, drag and drop improvements, and various bug-fixes. In total there are 24 known bug-fixes for Wine 1.9.5.
The list of Wine 1.9.5 changes -- including the heavy Direct3D work over the past two weeks -- can be found via the official release announcement at WineHQ.org.