Zach here, also from Spark. We're definitely working on next-gen hardware now, haven't selected a final chipset yet.
Our hosted cloud is somewhat different from the open source version, and the differences will grow over time. As an open source company, the question always comes to "how do we make money?" Our open source thesis is to give away basic technology and sell advanced technology. Right now the biggest differences between our hosted cloud and the open source version is scalability; our system is designed to scale horizontally whereas the open source one is a single instance (although it could, of course, be modified). We are still deciding which features that are still in development will be open sourced, and which won't. We've learned from other for-profit open source companies (like MongoDB, for instance), that even after being on the market for years they're still trying to figure out which features to give away and which to sell.