Some more frequent actual beta updates can be neat too, as the devs get feedback on the changes they do. We're testing a beta which they probably have reworked quite a lot over the weeks. (In part to the massive feedback, one would assume...)
So a beta update before release would definately help testing the game out anyway 
Other than that I don't really need any dev diaries and changelogs if we can't test them anyway, I have full confidence in the developers (Although, as said, playtesting - especially for balancing and the like can never be too much.)
