I’m currently trying out ScribeFire. I’ve tried blogging clients such as MS’ surprisingly good Windows Live Writer before. So far I’ve kept myself to WordPress’ built in editor, which works increasingly well thanks to auto-saving and revision control, but having a text editor supporting drag and drop etc. as a browser extension seems worth trying out as a way to make publishing easier and faster.
Although all the major bits and pieces are in place, I miss a few things. So far mainly that WordPress’ own preview system isn’t employed, and that the editor doesn’t fetch WordPress’ different sized copies of images; these could be missing features in the current version, or impossible to impelement using WordPress current APIs, I don’t know. I won’t use ScribeFire (or Windows Live Writer) for posting, but these tools are probably worth a try (and they both support a whole bunch of blogging services).