As you know, I've been using your weblogger bookmarklet since it was released (or close to it).
One thing that's always irked me a little is that it doesn't have a "label" popup. I tried adding one manually by putting in the SELECT tag / OPTION tags from the #newMessageForm in my weblog page but then for some reason IE5/Mac didn't like that.
I had an idea this morning.
Instead of generating the form with the bookmarklet....
Create a WeblogView that "just" has the #newMessageForm macro in it. Open the URL to that form in the new window.
The "small implementation detail" ;-) that I have to figure out is how to get the page title/url/selected text into the page being rendered.