We already know that the Upcoming MGS 5 contains Huge, Open, Areas and other Features such as Base Building, not so much as in Ground zeroes as it serves as a Big tutorial to get Players back into the mix. But The Phantom Pain will contain all these and more such as Mission Creators etc not only being limited to Consoles but also on Smart-glass devices etc.
The newest features to Come into the scene are not so much as new in the series but will be Fantastic in the new open world theme.
Kojima said in an Interview just last week that Players will be able to send scouts to Recon the Map, Highlighting Routes and Areas which will help Snake through his Missions, Not much was spoken about it but I’m guessing it will serve much like the Scout feature in MGS: Portable Ops(PSP) in which Sending scouts to maps will allow them to Get Ammo and special items from the map they were assigned.
Another Feature Kojima talked about in a Alert Podcast was Co-op and having a Partner help the player in these missions. But unlike Peace Walker, thier wont be 4 Player co-op but 2 player, and Concept art for this supposed Character was shown to the people in the Podcast. The Podcast was in Japanese and was actually aired 4 months ago and has not been elaborated on properly until recent.
Their are also English Alert Podcasts which can be found here: http://www.konami.jp/kojima_pro/radio/kp_alert/podcast.xml.
MGS5 is shaping up to be a Milestone in the MGS franchise and no release date has been announced yet, but the game is expected to release before the fiscal year 2012.