A couple of years ago, I painted my furnace room floor with paint (?epoxy? not sure) made for garage floors, the kind with the little chips of colour in it. I love it! It's both tough and attractive. I would definitely do that for a laundry room if I had the chance, especially as you have a floor drain. My second choice would be vinyl composition tiles or linoleum.
Whether or not to frame out and drywall depends, it seems to me, on whether you want it to look like a regular room or you're happy with a functional exposed-pipes look. For me personally, the extra work would not be worth doing for the increment in attractiveness. I would install a ceiling unless it would be really low, and probably cabinets rather than shelving because it gives a tidier look.