I think last year, or the year before that, I saw something about 2 1/4" x 3 1/4" sheets. While that's more or less the opposite of ULF, will those still be available to order? Now that efke's gone I don't think I know of anyone who still makes film that size.
I think it's a safe bet that HP5+ and FP4+ will be available in this size. I'd love to see Delta 100 available as well, but I also have 120 roll backs for my little RB Grafex, so I'll be alright.