I haven't had any problems (or noticed anything super-cool) yet, but one point in the release notes caught my attention.
Can now navigate local books while off-line
I wrote about this when I first started using Coda back in November of last year because it seems like a no-brainer.
I tested the new feature and it works as advertised - if you add a book using a file:// url, the "you are not connected to the internet" warning is not displayed when you're offline.
Unfortunately, the warning does not seem to be automatically dismissed for locally hosted books.
For reasons explained in this post, I like to have local copies of books that are served by Apache on http://localhost. It seems as though viewing these books while offline still produces a warning.
Ah well. It looks like I'll be hitting CMD+R when trying to view local books without an internet connection for the foreseeable future. I can't really say I'm too upset, because in reality the times when I'm programming without an internet connection are few and far between.