I'll Start Us Off 1.That When You Register A 3ds Friend You Can See Their Mii In Mii Maker, Streetpass(with a functions such as puzzle swap and find mii (1 and 2) and you could have there friend codes for a game you both have such as MK7
-One Never Outgrows A Good Game(Pokemon)Official Chespin Of Pokemon Y Boards Official Chespin of Pmd gates to infinity board-
3. Better weekly Eshop updates & especially VC support (mixed with both Wii & Wii U shop, so you only need to purchase once to play on all systems. That, and being able to easily transfer the save file/state between systems as well).
Read the mania: http://www.fanfiction.net/~nonexistinghero In SA2, it's Super Sonic and Hyper Shadow.