Based on how I believe the industry is shifting, it would be appropriate for you to stay employed in the infosec area while pursuing the MBA. You can always get more technical certs along the path to your MBA.

In the words of master ship builder Andrews, "Go now. Don't wait."
TH13 - you hit the nail on the head there. All of us in our IT auditing department have or are getting our MBAs or Masters, then meebe going for the certs. Our management supports going after certs, just so we look better to our clients, for me that also include a monthly shower and shave, whether I need it or not. I have seen "kids" finish their bachelor's and go right into their MBA program, it's not even a second thought anymore.

Something else to consider... if you want a terminal degree, people may wish to also pursue a PhD in Organizational Management or related field. However, some organizations, or rather, the people in organizations, tend to still see PhDs as an indicator that you want to be a professor or scientist; at least in our organization. Me? I am looking to pursue my JD and focus on Intellectual Property...yep I love the "dark side", first auditing then legal - bwah-hah-hah-hah!

*ahem... also TH13 is correct the field is already shifting in IT and it's security related arenas, security is still important in the business, but employers want you well-rounded, and I'm not talking about maxing out your daily burrito intake. They want the technical, business and interpersonal skills... mad skillz. Basically, the end-goal, highly trained, educated and experienced IT generalists that can specialize if needed.