For Portugal, there is already a web store that sells non translated ebooks in portuguese
http://www.mediabooks.com/. And the catalog is growing relatively fast, since i have been checking it periodically. I expect that Porto Editora (the biggest publisher in Portugal) will have ebooks soon in its web store
http://www.wook.pt/, at least that was what i have been told.
Meanwhile there is already a good amount of ebooks in the brazilian market, where i usually get most of my material in portuguese language. Some sites i look sometimes are
https://www.gatosabido.com.br/
http://www.submarino.com.br/
http://www.portaldetonando.com.br/fo...o-pdl-f95.html
The ebook readers are not yet very popular in Portugal, so that is the main reason publishers have not invested a lot in the ebook market so far. But that is changing rapidly. The tablet phenomenon is happening in Portugal so that will inevitably lead to more investment in media content for them and consequently more content for dedicated readers too.