Great job on launching the private beta. It's a amazing switch from the previous communication play. Given most developers needs a platform to host lightweight web apps. Plus, there is a massive opportunity there to build the Heroku for mobile optimized site for mobile web or embed webviews.
Hiring/Firing is one of the most difficult thing for founders at early stage. I think trial type hiring is the key where dating before marriage is ESSENTIAL.
I have been talking about the importance of exercise with joel. You need to be able to operate at peak both mentally and physically if you want to have serious result in your startup.