I talked to one of the guys at CDP RED (good thing we're neighbors, huh?) and they're on it. Basically they need to enable the DLC for the GOG keys. I apologize for the trouble, the Polish version will be available as soon as possible. I'll post in this thread once I get word from RED.

It should be today. Firek is busy hacking servers with his l33t skillz at this very moment.

Or something.

It's beyond our control, sadly, since it's a content delivery issue from CDP RED, but they'll get the files up as soon as they can. That almost assuredly won't be tonight, given all the other server issues they're working on but will likely be tomorrow.

The Polish language pack should now be available. We're very sorry that you had to wait so long...

The English language pack should no longer be present among the DLC, but if it's still there, you can have the Launcher refresh its available DLC list by deleting the values under this registry entry:
HKEY_CURRENT_USER\Software\CD Projekt RED\The Witcher 2\Downloads
This isn't really required, though.