Nit-pickery: for no JavaScript, the buttons are Hide full list/Expand full list, but for JavaScript, they are See all kudos/Collapse kudos. Ideally, the buttons should be Expand Kudos/Collapse Kudos (or Kudos List; whichever) for both.

If I were to be a giant pain in the ass, I'd also point out that the float on the button makes it jump around a lot, and it can end up beside the last few lines of the list (instead of below the list) depending on your window size and the contents of the kudos list. I think the problem is it's really oddly-placed in the code, stuck in the middle of the sentence like it is.

It'd be nice if "x more users" (maybe with a title attribute) were the expander text instead of cramming a button in there. Heck, even something playful like "(list 'em!)" after "x more users" would work -- we do have playful messages elsewhere! -- and be a little more explicit about what it did. Whatever the text, we could style it a little differently to make it stand out. We'd still need to do something like "(Collapse kudos)" link after the "left kudos on this work!" part of the sentence, which I'm not totally in love with, but I think it's probably an improvement over the current state.