Blogger Data API + TinyMCE + Dropbox
I've talked about how much I hate the Blogger visual post editor in some of my previous posts and won't mention the reasons why again here. Google seriously needs to put some effort into giving us a better tool, it fails miserably in comparison with WordPress and other modern Content Management Systems.
It may be possible however to create a far superior custom administrative backend for hosted Blogger accounts by taking advantage of the Blogger Data API, TinyMCE and Dropbox.
TinyMCE is an open-source LGPL licensed visual HTML editor that puts the Google Blogger WYSIWYG editor to shame. I believe current WordPress versions use a variant of this (but I could be mistaken).
All that's left afterwards is to customize whatever template you're using with links to your custom HTML page hosted on Dropbox, i.e. re-pointing the Edit Post links, etc.
I'd really like to give this a go if I had the time...unless someone else has already beaten me to it?