For those wondering about the next step in mobile chips from Nvidia here is a link to the GTX 860M from the guys at notebookreview, which has been confirmed as the mobile version of the GTX 750Ti.
Post #397
http://forum.notebookreview.com/gaming-software-graphics-cards/745074-new-details-about-nvidia-s-maxwell-40.html#post9584705
Post #397
http://forum.notebookreview.com/gaming-software-graphics-cards/745074-new-details-about-nvidia-s-maxwell-40.html#post9584705