probably not.. that would mean instant fork..

"We're not going to close functionally in the open source project, but rather we will address the items that small companies don't need but the bigger companies do need."

versus

"Today NGINX powers [..] over 20% of the top 1000 busiest websites around the world, including Facebook, Zappos, Groupon .." http://nginx.com/nginx-venture-funding.html

I don't think so. I looks like they plan to add some "enterprise" functionalities that will be available using a privative license.