WordPress 3.4 is out today and if you haven’t already begun the process of updating, you should. It should go without saying that you should be testing the update before applying it to a production site – but don’t put things off – updating is important.
The new 2.7.5 release has been tested with WordPress 3.4 and it is compatible. If you become aware of something I might have missed, be sure to let me know.
Version 2.7.4 has also been tested with the 3.4 release and it also works.