With 2.6.1, we’re continuing our trend of releasing a maintenance release shortly after a major release in order to get fixes for the inevitable “dot zero” bugs into your hands without a long wait. If you’re happy with 2.6, however, keep on using it. You need not upgrade to 2.6.1 if 2.6 is getting the job done.
2.6.1 offers several improvements for international users. Styling of the admin for right-to-left languages is much improved thanks to the efforts of the Farsi and Hebrew translation teams, and a mysterious gettext bug caused by certain PHP configurations is now fixed. For IIS users, 2.6.1 fixes several permalink problems. Image insertion problems in the Press This feature experienced by IE users are also fixed. Of note to everyone is a fix for a performance bug in the admin where those with a lot of plugins would experience slowness on some pages.