Big Mistake
I use some Yahoo services through my google login, mainly becuase it's easy and I didn't have to sign up for anything else. Once they make this change, I will stop using Yahoo, and so will thousands of others, probably.
Big mistake
what do you expect they want their accounts to be used for their products pretty much, dont see that driving away as many as you think, a lot of people have some type of yahoo account already
I have to think that if there was a large number of uses who do not have a Yahoo! account but log in through Facebook or Google that they would keep the option.