The official version of WinSCP is meanwhile 4.1 beta, the portable version is still 4.0.7. At winscp.net you only can get the German language file for 4.1. So average users of the current portable version don't have the chance to localize this application.
To avoid such difficulties in the future: Is it possible to use the "WinSCP Multilanguage installation package" from winscp.net as the base for the development of the next portable version? This would help all non-English users.
The official version of WinSCP is still 4.0.7. 4.1 is beta and beta means a software isn't ready yet. They have it anyways so I think they make it available for testing purposes. And many of the translations seem up to date on the Translations Page so I think they should work even with the latest beta.
"What about Love?" - "Overrated. Biochemically no different than eating large quantities of chocolate." - Al Pacino in The Devils Advocate
Did you try to install WinSCP Portable 4.0.7 with a German language file? I think you didn't. The only German language file available at winscp.net doesn't work with 4.0.7. So at the moment there is no chance for Joe Average to use WinSCP Portable 4.0.7 in German language. *)
My proposal for the developers of WinSCP Portable: Please use the Multilanguage package of WinSCP to create the next portable version. So problems of this kind could be avoided ...
*) I managed to get a working German portable version, but I'm not Joe Average