Wow, I really didn't think I'd get any response at all. To the "regular" flower lover they don't look that showy. But they are different, and I expect them to mature as a more unique form, too. Flowers should be larger once in the ground, although the species is normally small flowered.
Anthony, I suspect the main attributes for breeding with L. callosum will be for vigor and flower color. It usually has a more unique flower shape too: with very strongly reflexed petals that curl back tightly. This characteristic did not show up in my seedlings, but I think it will with more maturity. Unwanted characteristics might be height and long pedicels. The species is not closely related to any other lily, but most closely related to L. amabile. It might cross with a slew of other asiatics, so crossing it with just about any asiatic hybrid is worth a try.