Get it here.
There are mostly bug fixes in this beta over the last one. For example, refreshed categories will now be saved correctly when you are posting an entry to a blog. When syncing a document with an iOS device for the first time, there will be an extra message saying so just in case that is unexpected.
One change that you might not see is to how MacJournal deals with changes from other device using the same data over Dropbox. While opening the same place on more than one machine was never recommended, it sometimes happens and this release should hopefully handle it better by merging in the changes from the updated file on disk instead of wholly replacing the opened document, which may have some unsaved changes.
Please give this a try and let me know of any issues via the Report item in the Help menu. Thanks for trying MacJournal!