Congratulations to the WordPress team and the more than 100 contributors who helped to bring this release to the public today.
There are loads of changes, which you can read about in the announcement blog post. Among the most interesting changes for MarsEdit users is the addition of more intelligent “post status” information for blog editor clients. Practically speaking, this means the problems I described in my MarsEdit 2.1 announcement will no longer be an issue for WordPress 2.5 users.
But… Ugh, it looks like I messed something up and MarsEdit 2.1.2 doesn’t accurately detect these statuses on WordPress posts. I will try to get a 2.1.3 out soon that fixes this so we can put the post status problem with WordPress behind us for good.