So I took a look at Blogilo a few days ago. So, taking a look at my Blogilo post I have to say that it is pretty much ALMOST there for the perfect offline blogging tool for someone using WordPress. Sure, it doesn’t allow your to create categories, but a blog like mine that’s been around for ~7 years probably has all the categories it needs. The extra fidelity can come from tags which Blogilo hands just fine.
I mentioned that it doesn’t list the categories hierarchically, but that’s barely even an issue. The biggest issues for me are the lack of captions for images and the fact that uploaded images don’t automatically link to the images. In all of my images, I have them set to link to themselves so if you want to see it full-sized (pretty important when showing screenshots), you can. Blogilo doesn’t have that ability and that’s what pretty much kills it for me because that’s so important to me as a blogger. But I’ll talk to them on irc and/or submit a bug report for that feature.
I think if they just solve these little issues, Blogilo will be the BEST offline blogging software and might even give the WordPress native interface a run for its money.