Am I being silly or are there bigger sample images available yet?
It has been a while since I was in US or JP, but from memory prices in both countries exclude sales tax right? What is the "going rate"? UK £300 ex. VAT would be £250.
As for comparing prices to the US for a JP company, that can work. If you look at currency conversions, it all balances out. If it didn't, people would exploit those differences by changing money between them and make a profit.
I don't know about other countries, but historically in the UK, lenses seem to be released at full RRP for pre-orders and shortly after launch. Depending on availability and market forces, it will tend to quickly drop to a more reasonable street level after some time. The bigger question is how much and when, but you tend to see faster drops early on, before the slower drop or even flat price over the longer term. I don't know if there is much of this effect in other countries also.
Back to the lens itself, I find myself likely to get one. I used to have the old variable aperture Sigma before I was on Canon and never got round to replacing it, making do with a fisheye instead. Not quite the same I'll admit. To me personally, the speed difference is not significant as I'll be using it around f/8 anyway for more depth of field and better sharpness across the frame. It will be used more at the wide end than long end so I wont miss that. Focus speed? Is that really important for a UWA? Give it a little time and it will be half the price of the 10-22, and I don't think you can complain about the value there.
Side note: for the 10-22's money, I'd rather be looking at the Sigma 8-16 anyway...