This is hilarious.
Very nice concept. But I don't think that this will really goes well for UX. Imagine the password form and then you display the information
1 special character,
1 number, etc. in the placeholder using superplaceholder.js. What if the user uses TAB to navigate to the input and instantly starts typing? The information will be hidden and the user will get an error message...
Well that is something we can assume, but to actually see if that happens or not, in my opinion, we'll need to see how its adopted and used on websites.