Anything is possible if you're willing to commit the resources to it. The Japanese use cellphones to an extent unparalleled in the US and Europe, displacing most computers. If you look here, you'll see Toshiba was shipping phones in Japan a year ago with screens similar to what Apple is using in the iPhone 4 as well.

The downside is that carriers over there are worse than Verizon ever was, and the software is just a touch above feature-phone level. A good number run Symbian, but hide all the Symbian-ness behind a custom layer.

The market over there is so vicious (6-month product cycle, ~18 month end-user refresh, and low unit counts) it's no surprise that Nokia doesn't really participate (the Korean and Western brands only participate to a very limited extent.)