Patch 1.5 was released today, as announced on the official site. To install it, you need to connect to the game and run the updater. Alternatively, you can download single .EXE files by using the same URL as the other patches, but change the number to 1.5:

Along with online/offline savegame compatibility (which doesn't seem to work properly), town screens (which are beautiful) and the DLC Pirates of the Savage Sea if you bought it (you need version 1.5 for it to work), the patch contains a whole bunch of bugfixes.

The full list of contents can be found here.