Not sure if it's been stated before or not, but I don't think it has. However, there was a video posted back in February stating that Lenovo would be shipping laptops with the Radeon 400 series in April (this month, specifically the Radeon R7 M460). If this is indeed true, those of us that are hoping for a solid dGPU in the next rMBP may get what we want. Here's the link to the video: