According to an interview with Hideo Kojima in the latest issue of Famitsu, as reported by AndriaSang, Konami is holding a Metal Gear 25th Anniversary event on August 30th, where something new will be announced by Kojima and co.
The new announcement is related to Kojima's vision of connecting people, with Transfarring serving as a test for this vision.
Info is vague, and there is no direct mention of Metal Gear, but with it being announced at a Metal Gear 25th Anniversary event, and having to do with Transfarring and running on Kojima's new Fox Engine, all signs point toward something Metal Gear related.
Also, coming out of this interview, is the confirmation that Metal Gear Solid 4 will see a budget "The Best" release in Japan, and with that, a trophy patch—something fans have been clamoring for ever since the PS3's 2.40 firmware update, when trophies were initially enabled for the first time.