Upload image class needed — what happened to imagelink?

I just upgraded to version 2.6.5 and I’ve got a major design problem on my hands. All because WordPress no longer appends the “imagelink” class to images when I upload them.

In short, adding a class to links that happen to be images is essential for designers who want to style linked images differently from linked text. Without a special “imagelink” class, any styling a designer performs for text links also works on images. So, for instance, I’ve added a border-bottom and background changes to the :hover behavior of text links, but now it applies to all linked images and makes my blog look dopey. Results viewable here.

Speaking in more technical terms, since the <img> tag is always within the <a> tag, there’s no way to style <a> tags that wrap images without a dedicated CSS class.

At this point the only thing I can think to do is create a plugin that somehow scans for linked images (yikes, I have no idea how to write a plugin), or modify the application code — which will just get overwritten when I upgrade. Can anyone think of another solution?
Thanks.