MTV News spoke to Stallone at CinemaCon 2012 and this is what Stallone had to tell them:
On EX2: "We do up the ante. We have a bit more money," he said. "When people go in there, at first they say, 'Well, it's not [Robert De Niro's] "Deer Hunter." ' And I say, 'Of course, it's not "Deer Hunter." It's a bunch of mugs having a good time and just kicking each other around.' It's male pattern badness.

On EX3: he was then asked where would a third movie go from there? Stallone said he doesn't yet have another team of thespians in mind for a threequel.
"There's one or two, but there's not enough to do a whole [movie]," he said. "There are guys who are good, but they're not of that ilk. It's very odd that becoming an action guy is kind of like the ugly stepchild, like, 'Oh, you didn't make it.' It's very hard, because if you notice, there's only been about six action guys in my lifetime that have somewhat made it, because it's a very odd, odd combination. Guys have to be somewhat entertaining. It's not about muscles, per se."
On Rambo V: Stallone further added that there's another story in his beloved "Rambo" series yet to come.
"There's a volcanic eruption for Rambo. The magma of Rambo is coming to the surface," he said. "I know there is [another story]. You know when you lay down the final culmination of your life and you can articulate it, but also act on it, and he realizes what his destiny really is. And it's not to be a farmer, it's not to be obscure, it's really to go out in a blaze of glory — in a heroic fashion. But is he really doing it for himself or is he doing it because that's just his id? That's just who he is?"
Well, all is said...