Here's the latest after a week.
I watered it a little bit last Sunday, and then again the Sunday just gone. I'm going to skip this coming Sunday to see if it perks up, and in case I'm overwatering him. His soil's not as fast draining as I'd like (but just the soil it came with, though I don't want to repot it until I know it can deal with the stress).
Its two largest leaves are starting to yellow, and its third largest is very limp. I'm sure I heard somewhere that even if it loses a lot of leaves, they'll grow back.