I've lived in Vietnam for the last 4 years and got used to the 'bum gun' as we call them. It is awesome.
I came back to the US late January for a meeting in SF. I was staying at my friends house and lamenting the missing gun. My friends were refusing to install one because they were afraid that their two year old would use it to soak the entire bathroom.
I started checking Amazon anyway... once everyone started stockpiling TP, the prices started to rise and I started to see more and more of them marked as 'unavailable'.
Now there is definitely no chance they will get one in the near future...