Speaking to IGN, Metal Gear creator Hideo Kojima once again talked about the possibility of a sequel to Metal Gear Rising: Revengeance, which was developed by Platinum Games (with Kojima and crew operating in an advisory role).
However, when it comes to the main series, Kojima stated that, “Numbered titles in the series will always be created by myself, or at least created at Kojima Productions.”
This means that other developers would be working on spin-offs, and that too only if they know how to make it work within the framework of the franchise. For example, it was Platinum’s understanding of just how Revengeance could work that saved it from developmental limbo when Kojima Productions was behind it.
Also in regards to next generation hardware, Kojima expressed interest in how players socially interact and play the game through different devices rather than on whizbang graphics or more powerful technology. Hopefully we can see his vision brought to fruition when Metal Gear Solid: Ground Zeroes is fully revealed (for this generation or the next).
Source: metalgearsolid.nl