Getting back to the hardware selection part of the thread, I think there are a number of things that it would be handy to have more hardware and programming options available in the interface.
In addition to COM port selection, I wonder if it would be useful to be able to adjust upload speed.
Similarly, in addition to board reference design, I wonder if folks would find it handy to break it down to the actual AVR chip (ATmega8, 44, 88, 168, 328, 644, etc.), clock speed (1, 8, 16, 20MHz, etc.), and reset method.