It's no longer a secret:
Schleich brings 2011 a set of 5 boxes each with 5 smurfs as a 50 years celebration (???). Price in Germany 18,50 Euro each box. I have a pic but should not publish it at the moment.
We will see what the markings are at the older smurfs
No 41255 = 1960 - 1969:
20001 Papa
20002 Normal
20007 Schwarzer
20008 Verschwörer
20009 Trommler
No 41256 = 1970 - 1979:
20031 Brieftraeger
20037 Arzt
20042 Kuechenchef
20045 Kunstmaler
20098 Ballerina
No 41257 = 1980 - 1989:
20117 Fuellhorn
20138 Gaertner
20145 Bauer mit Sense
20152 Mueller
20160 Apfel
No 41258 = 1990 - 1999:
20440 Wettschwimmer
20441 Sprinter
20457 Aerobicschlumpfine
20460 Golf
20468 Kletterer
No 41259 = 2000 - 2009:
20525 Torwart
20526 Bankdruecker
20527 Spielmacher
20531 Fan Schlumpfine
20532 Manager
edit/update:
The boxes looks very similar to the one from Toys R Us, discussed in this topic,
except the new 2011 ones have a sticker or a print in the left top corner of background where the tree is, telling e.g. "1960-1969 EDITION"
This is a pic in this topic from André