Not to get our hopes up too much, but Konami is currently hosting a survey about Metal Gear Rising: Revengeance that, after going through a bunch of highly specific questions, gauges interest in a follow-up game. You'd like one of those, wouldn't you? Me too.
Specifically, the survey asks: "If the sequel to Metal Gear Rising were available, what would you expect from the game?" Options include a longer running time, more of a connection to Metal Gear Solid, sci-fi and stealth elements, and more cutting, to name a few.
While we daydream the possibilities, there's still the upcoming PC version of Revengeance to anticipate.