Ick. Since you don't see what all the fuss is about, you're going to put another doodad between your user and conversion. Ask an online business that does any sort of volume at all: this is bad.

Web forms are where the usability rubber hits the road online. When adding an item to your form you should always be of the mind set that this extra step (optional or not) will lose you conversions, but you have to have it because of X. This forces you to justify placing item X, which in this case is the unmask password option. Is having an option to unmask the password field going to gain you more conversions than not? I have no data, just anecdotes and experience, but those all tell me no.

Putting a check box next to the entry field is putting GUI decisions on your user because you can't figure it out, and it will lose you conversions.

EDIT: Re-reading this it sounds like personal attack on the OC. It's not. I'm using the universal you.