Even more "differently" mobile
There's a free blogger.com client for the Iphone called blogwriter lite; it runs as a scaled up portrait only app on the iPad. This also means that it uses the iPhone soft keyboard, not the native iPad one, which is usable but not nearly as good as the real thing. It does provide offline writing, though, which is probably enough reason to use it anyway; I haven't checked to see if writing in Notes and pasting works with emulated apps or not, though it really should.
In the end I've done more testing of mobile blogging tools than I've done actual mobile blogging; seems that when I'm mobile I don't actually have time to sit down and write, even if I have the tools...