The problem here is that nobody can release a similar device and get adoption because they don't have the content. Similar to iTunes and the iPod. I'm pretty sure this is going to be a device monopoly.
The only people that could pull off a licensing deal would be Barnes and Noble or Borders and they don't seem to be in a position to do that. At least Apple has the Zune Store as competition (as much as it sucks). Amazon's going to have nothing. Sony can't compete on device technology alone without the ability to get content onto those devices easily.
If the release comes from Japan, it will start in Japan, with Japanese content. Tie-ups with B&N would be a good deal for both sides. The Japanese have talked about this for years. One of the first targets would be the newspaper publishers. They have the infrastructure to pull off a wireless distribution channel from the train stations. (curiously this didn't happen with Sony).
