I think people are more inclined than you think they are to enlarge the thumbnails on a regular basis. When I look at the new photos added each day, I enlarge almost all of them because so much detail can be lost otherwise. I'm sure many others do the same.
I just want to go on record to say that I don't see the need for change. I like the thumbnails just the way they are, and I can't be the only one. I appreciate their symmetry. I don't want them to be different sizes or the same size with white margins. Neither of those "fixes" appeals to me aesthetically.
