Hi Rick,
I can second iaccess - we do the same with an Italian and English website, with the English version in a subdirectory and it all works very well in ranking in both languages.
There are only 2 things you should watch out for - for the English version of marketing, emails, etc make sure you have an easy URL for them to type in instead of
www.example.de/en but rather .com for example - they will invariably forget the /, just ignore the URL, or end up at the German version and leave without bothering to look for the language change link.
The second thing is make sure that if they land on an internal page and click the language change link that they go to the equivalent page in the other language and not back to the homepage - even with very clear and good navigation nobody wants to wade through your site to find where they were at.
All the best,
Alex