Log in to the Ovi Store from your phone and at the top of your home screen you'll see "A special gift from Nokia" "Download Premium Apps" all blue and pretty big. It can also be found in "Collections".
There isn't much info about this freebie but from what I have managed to find, you have 30 days from the first log in download what you want so long as you log in before the end of December.
I can only see 6 apps at the moment (per my screenshot) but I think more are getting added as time progresses.
If not, these are still free so pretty good.
nokia has an app store?