I can confirm this plug-in also works well with 2.8.4. One minor issue I have not sorted out yet is translation of the theme stuff. Seperate posts have all there thingies (editor, date etc.) nicely translated in the theme (not the content itself, but the theme stuff) when served.
Inline posts, which come with a page, however, show the theme-stuff in english (the default language). Is this a bug or does the plugin also require some sort of language setting?
I love the concept of in-line posts. This way you can organise/control your webstructure by using pages and subpages, yet fill them with content from your posts. But the translation must follow the setting of the site.