Seeing this just prompted me to visit the Escalation Studios site and I notice that Severity is no longer listed on their Projects page. It's getting on to three years since they announced it and we haven't seen a screenshot so it looks like they've given up.
There's an "unannounced project" listed for the Wii so clearly they're also listing games in development. I can only assume this means Severity is no longer in development. If you're interviewing Tom Mustaine ask him what the situation is with Severity.