I don't think the Nook will ever go worldwide, but it might come to Canada and WiFi should work anywhere.
The other option, particularly if you like your PRS-300, is the Sony Daily Edition. This is likely to come to Canada at some point.
All three devices (Kindle, Nook, PRS-900) use AT&T for 3G, and so the hardware should work "as is" in Canada, providing the vendors setup deals with wireless providers.
If you go with the Kindle 2, then you will have to convert between AZW (MOBI) and ePub (stripping DRM) to move ebooks between devices, but this does give you access to both Amazon and Sony/Adobe ebook stores. TOPAZ ebooks will have to be read on the Kindle or Kindle 4 PC (or avoided).
We don't yet know if Nook ePub DRM can be circumvented, even though the related standard Adobe ePub DRM and eReader DRM have both been circumvented. If not then you would be locked out of the B&N store if you also want to read on your PRS-300, but the Nook will read standard Adobe ePubs.
|