A few reasons it's doing so well in Japan (based on living here) -
1. Canon's advertising a marketing campaigns are effective, when somethin new comes out you know all about it!
2. Japanese people love new gadgets, especially cameras.
3. It's small - they love small and cute things that come in multiple colors.
Exactly. Small powerful, trendy and great marketing behind it. I am sure it will do well in other parts of Asia as well.
I won't be getting one, and I do find it funny when I see pros sticking it on super tele zooms like the 500, 600 etc. I think they were just playing with it. At least I hope they were. And as for the AF it is slow even when using the viewfinder, as someone already described it hunts, focuses, goes hunting again and then locks.