Just downloaded and installed and posting this via Open Live Writer. Remember the lovely (but dead) Windows Live Writer from Microsoft? Well this is a forked version of that which is open source, based on MIT license.
The editor is offline and is very similar to word and can support a number of blogging platforms – including the common ones as you would expect. You can muck around the code (zip) or check it out on GIT. It is still work in progress of course (e.g. Plugin’s are not implemented yet). Irrespective, hugely grateful to Scott (Hanselman) to get this going.