This week I mostly cleaned up a bunch of internal stuff, artifacts of MeTal's rather crummy origins -- for instance, methods in their own "utility" modules, instead of in classes that they are ostensibly part of. I did a lot of dumb things like this early on, and I'm now sorting it out and setting things right.
Right now, I'm mainly supporting my own case -- exports from a bunch of old Movable Type blogs. To do this, you need to supply a template that exports the blog data in a JSON format (I'll provide examples when I ship). The JSON can include details about a blog's text and metadata, and also about associated images, categories, tags, and other attributes.
I have some of this stuff working, but not all of it. Categories, for instance, don't import properly yet; that's something that needs to be working sooner rather than later, as I have a number of blog items that depend on category hierarchies to be useful. I also have to figure out how images are going to be handled -- for instance, whether to supply an option to copy the images into the target blog's asset directory, or to leave that up to the user.
At the rate I'm going, I should have one of my blogs moved over to the new system by the end of the year -- meaning that support for imports should be pretty robust by that point.
What I'm dreading most is having to reconfigure the import routine to deal with WordPress's XML export format. From all I've seen it's not documented well -- but I have more than a few WordPress blogs running elsewhere that I can draw on for test data.