I'd love to see someone breathe new life into Contra, but probably not anyone Konami will allow Cox to work with.
If it retains ridiculous setpieces, a frenetic pace, no reloading, no waist high cover dickery, and a sense of humor, I'd like to see what would come of it. I definitely see at least some of this in, say, Bulletstorm. Say what you want about the actual humor or whether or not the plot was meant to be tongue-in-cheek, but goddamn, some of those situations were simultaneously hilarious and epic in a way very reminiscent of Contra. Giant Robot Wheel of Death, anyone?
But any time someone mentions either the phrase "Call of Duty numbers" or "broaden the userbase", I die a little inside.
I'm going to echo something else from Jim Sterling. You want to go for the CoD audience? Don't. Please don't. It never works. The folks who play that game want more of that game. They're not going to give a shit about something like Call of Duty because they've already got what they want. They make a new one practically every year for Christ's sake. Do something different with the franchise, sure, but don't just ape shit that already exists (and is infinitely more popular to boot).