Since various threads already mentioned it I was eager to try out how it works if you change the klanguage of the game. So I switched from german to english and Steam started to download the file Skyrim - Voices.bsa, a file which is around 1.3 GB in total. Although having a good and fast internet connection it took several hours to complete the download because the Steam servers seemed to be overloaded.

Dear Bethesda:

If you are planning to continue to distribute your games via Steam and to make games available in mulitple languages please consider to change the technique behind this. It would be great if you just have to download another language file once but not eevery time you wish to switch the language. It could be so easy: name the language files differently and make it possible to switch via config file.

Dear Steam: Please consider updating to more powerful servers...