Would love to see more extension in the image uploadeder. Take a look at Typepad or MT's image handling -- the options are really nice.
Typepad has an interface that allows users to choose handling options (i.e. align left, align right, etc). It's nice user friendliness for folks who don't necessarily want to add (or know how) image handling in their CSS or in the image code itself.
MT does nice thumbnailing - allowing a user to determine the actual size of the thumbnail, itself with each upload instance.
Even nicer would be the ability to not only determine the size of the thumbnail - but some type of edit interface that allows the user to determine which part of the image is to be thumbnailed.
All of this in teh inline editor - - with a tag to allow users to easily place teh thumbs in their sidebar - clickable to a gallery page.
MT allows the nice ability to create a photoblog that way by using the extended entry and excerpt feature.
Getting the photoblogging down solid would bring more users, I think. Each of the gallery plugins out there lack one thing or another - - plus making the image handling more extensive and user friendly will allow WP to live up to its user friendly rep!
Thanks for the opportunity in the ideas forum - great idea, btw!