And as for today we have 311850 customers (over 100k in the US)
Interesting. That implies that although the USD transactions account for much of MtGox volume, the majority of MtGox customers are located outside the US.
And when you break it down further, it equates to each customer having ~15 BTC each or less, assuming 622,000 total bitcoiners. I guess about $5M cap is something to be in awe about.
I am impressed with the 311K figure regardless of what each/any have on account. It's possible there's a million bitcoiners in the wild, considering a rough extrapolation.