Take your time Dan. With the additions you’re gonna make to the new version it will pay to be a little patient :). Also, I’m having some difficulty with the necessary upgrade to 1.5 beta ;).
I hope you succeed in the sort_order thing (most recent on first page). And the other folder thing for the gallerycontent instead of wp-content. And, and, and…
No really, it sounds already great.
Something I just thought of would also be nice. Just an idea, but wouldn’t it be nice to have this sequence: thumbnail, then clicking for a larger image, then the possibility to click for the original image (even larger). If this largest image could be passed as a variable to a picturepage.php (template) which could have it’s own markup and style, the three images together could fit perfectly into the look and feel of the blog, just like your example with the rabbit.
Most of the plugins call the largest image as a jpg into an ugly and mostly empty _blank window, with the image aligning to the left. But in this case it could be made to look like anything you want.