IPB ran on one developer for years and years, it was only about 3 years ago (IIRC) that Brendan Faber joined as a full time Dev, prior to that IPB was entirely designed/developed/coded by one person.. Matt
The fact that Xenforo had two brilliant devs from day one is one of the reasons they were able to develop so rapidly.
I don't believe we need more devs, just more patience