Is having urls like: de/product-name-in-german.html and en/product-name-in-english.html pointing to the same product but in different languages a good practice considering SEO? Does this count as duplicate content?
If the two pages are written in different languages then the content is definitely not duplicate: the text is different, no matter what product it refers to.
Matt Cutts (the Google Web Spam guy) said:
If the content is truly the same, I would pick one domain and make the other domains do a redirect to the domain you prefer. For example, google.com could do a permanent (301) redirect to www.google.com, and then we would see that and generally choose the destination of the redirect. Having content from two different domains isn’t risky if they are in different languages (for example, Chinese and English), but if you have the exact same content on two different domains, it’s better to use a permanent redirect from the duplicate domains to a single preferred domain.
If you have mirror pages without a redirect, that can cause issues. It’s better to use 301/permanent redirects, because Google might choose to remove or not to show the copy that you liked the best.
(source - http://www.mianfeiseo.com/2010/05/13/zac-interview-matt-cutts-en/)
It won't matter, as the content is not duplicated and the URL's are different. The only thing is that in the future if Google decides that they will be smarter on people having a website duplicated in a different language word for word. This is obviously out of your control right now, but the translated text is just fine for now. Many people do it to get rankings in other countries (from the origianl content), and even put iton completely seperate domains.