It looks like the early reviews of Apple’s Journal app from those who blog and journal already (in other words, those in the practice of writing regularly) is that the app is quite basic, and although the entry suggestions are nice, the writing experience is not as good as Day One. I guess that’s good news for Day One, in that there’s no risk of them being sherlocked.
But Automattic shouldn’t rest on their laurels. There are a few things I’d like to see them add to Day One, such as image captions (oh, I really wish for image captions) and maybe a nicer reading experience when you just want to browse your journal (the sidebar and editor just doesn’t work for me when I just want to browse the entries).
So, yeah, Day One position looks to be secure; but that’s no reason why it couldn’t be made better.