Over here in Canada, I bought the steel case (or 'steelbook', as some call it) version from Future Shop (an electronics media store exactly like Best Buy in the U.S.A.). There is only one style of steelbook available for this movie, worldwide.
The steel case has an upper body shot of Clumsy on cover, waving.
The 3 discs include:
1. 2D regular dvd copy
2. 2D Bluray copy
3. 2D reglular dvd copy of 'The Smurfs: A Christmas Carol' (though this copy is in a loose paper disc slip, and does not have its own holding spot within the case)
The special features are split between both the regular dvd and blu-ray copies. With this steelcase version, all known special features are available (unlike if you bought just the blu-ray, or just the regular dvd)
This steelbook version is available only at three countries worldwide and in limited numbers:
Canada (online and in-store retailer 'Future Shop'); limited number is unknown to me, though I read online that it's most likely 1000
Italy (online only at wesite www.DVD-store.it); limited number is 1,500 and each steelbook has a tiny sticker on the front cover with a number stamped on it, telling you what number out of 1,500 you have.
Germany (retailers Mediamarkt and Saturn - don't know if their online stores will offer this as well; also, online at website www.amazon.de). limited number is unknown, though I read online that it's most likely 1,500.
Depending where it was bought, each of the steelbook content is different. The Canadian version details were already described above.
Italy: 1 disc - 2D blu-ray and 2D regular dvd on one disc.
Germany Mediamarkt/Saturn: 1 disc - 3D blu-ray and 2D blu-ray on one disc.
Germany amazon.de: steelbook packed in cardboard packaging along with 3 loose movie Jakks Pacific figures (same as what is currently in the market). They are Papa, Smurfette and Clumsy. 2 discs - 3D blu-ray and 2D blu-ray on one disc. The other disc has the 2D blu-ray 'The Smurfs: A Christmas Carol'.
Special features are included on both the Italian and German copies, but I don't know to what extent, unfortunately.
Hope this information helps. I may post pictures of these later, if they are easy to find on the internet.