Let me start by saying this is not a request to make MarsEdit work more like Tumblr. It's just a UX observation that I think could help improve MarsEdit.
When you create a new post on Tumblr's site, there's a big green "Create Post" button that, once tapped, will indeed create and publish your post. But if you change the post status from "publish now" to "save draft," that button's label changes to "Save draft" to help reinforce that the post will not be published now, but saved for later.
On a few occasions, I've set a MarsEdit post status from "Published" to "draft," spent some time crafting the post, then hit "Send to blog" because I want to add images up in the CMS, share it with my co-writers, or what have you. Then I crap my pants because I couldn't remember if I had indeed set it to draft, so I rush to log into the web CMS and check to make sure.
It would super neat if you could consider making the "Send to Blog" button label match the post status if the user changes it, helping to reinforce exactly what's going to happen to that post once it floats up to the cloud.