If Shelley wants to do some mock ups, here is a more detailed "working" of the Galleria system as it will be in v1.0. Unlike albums in vBulletin, this will be a site wide gallery system to begin with. I plan on expanding it to user albums within the next major version (all sub-categories of a category named after them, a sub-category of a "User Albums" category). That being said, the gallery home page will be structured very similar to XenForo's home page with a side bar that includes latest images, a featured image (if wanted), statistics, and other random stuff. The categories will display like nodes, and a category can become a node (well, the node will be a wrapper and pull all the categories information) so it'll display on the homepage if you'd like.
Inside of each category, a thumbnail listing of all the images will appear with information such as comments, etc. Clicking on a thumbnail will bring up a jQuery popup with the full image (well, larger size). Clicking the image / title will take you to the detailed information page where you can see comments, like, report, etc. and clicking on the image in there will resize such as XenForo does. I may include Google maps integration for locations, etc. Thoughts on what information required / wanted to be associated with an image is there. But the only UI I want to be a surprise is the actual upload (all though, your suggestions are more than welcome) screen, because I think I have thought of a very creative way to set that one up.
The back end will be a simplistic nature that'll work just like any other ACP page. Only cumbersome thing will be creating the nodes.