I was surprised to run across an app which claims to have this ability. After discussion with the developer they say this feature was added in 3.4 back in June. I did some searching and came up with this:
Thanks, yes this is promising. It still will take some work on my end to support it but this is a good start. Usually the way this works is once the API supports it on WordPress I can put it on my list to try to implement. Bear in mind there are complications for example I need to deal gracefully with the fact that the blog might not be updated to 3.4 yet. Anyway, there is hope now ...
I would really like this feature too. In fact, it is essential. Right now, I have to upload my post via MarsEdit, then go into the WordPress backend and select that image as my featured image. Thanks.