I asked lenovo tech about this as well, they told me it would be released in some months, they told me that the y410p ultrabay upgrade would be coming this july, passed by. now i am hearing it won't be released at all for the y410p, at least any time soon.
moral of the story: lenovo support is awful, if you talk with multiple representatives, they will all tell you something different sometimes, you will just have to take a chance or simply wait before purchasing one. as said above the 650m is available right now for the y500 along with the y400.