Very impressed, been looking for something like this for a couple of weeks. Are you planning on adding 'comments' functionality.
Do you have any plans to make it possible to use an orb for blogging?
One very simple way to turn a wiki into a blog is to add shortcut for "todays page". The shortcut should open page "/blog/yyyy/mm/dd" for editing. It is a killer feature for me in Zim desktop wiki (http://zim-wiki.org/).
You will probably have to add some sort of pages-listing-child-pages, but it shouldn't be very hard. I know, because I have tried it myself for a wiki I have been developing ;-)