<p>Done often, yes, but not all time. Some ‘purists’ like to see this as a sign of weakness of the presenters, but I tend to give the artistic team that made this choice the benefit of the doubt. However, as a listener, of course I’d much rather hear a project in the original language that the libretist and composer collaborated in.</p>
<p>Depends on the opera too. Some have translated versions that work well, (in some rare cases the composer even wrote the piece intending for it to be performed in more than one language!) and have become popular on the stage in multiple languages even with world class opera companies. Strauss’ Die Fledermaus, e.g., is very commonly done in English.</p>