Jmm, (this may be long)
You are correct that Bloggers "expect it to work"
Yedda widgets resize to fit in the area they are placed in. This is a cool feature that I don't remember seeing anywhere else. However, I think that some users will want to be able to control this feature. Lets say TechCrunch wants to do an article featuring a Yedda widget. They may not want it to expand to fill the posting area. They want it to look like it would appear in a side bar.
Branding
While deciding what to post i came up with the idea of creating a Grazr widget that pointed to a specific RSS feed. In this case it was The Blogging Times.com
I titled the post "The Blogging Times mashed widget"
My bright idea was to add the code for this widget to the post I was contemplating writing. This way anyone that wanted The Blogging Times content on their blog could easily have it. (I just wanted to mash something other than potatoes)
Grazr.com saw this post and decided to take it one step further by adding the "The Blogging Times" logo to the widget.
This kinda gives the impression that TBT has a widget. (even though they don't)
This is what I meant by branding.
Feedback
I do not recall any widgets that have this feature.
We, as creators, are sometimes blinded by what we create. (does that make sense?)
Feedback isn't just for bug reporting. It's also for ideas. Widget users have great ideas for functions that widget creators didn't even consider. Get enough feedback about a certain feature...You see where this is going.
Enough of the longest answer in the world. If you made it this far...let me ask you a question...How many times did you yawn during this post?
Derek