The Special Edition for Devil May Cry 4 truly is special. It's adding a couple of features and items that the original 2008 version didn't have. This includes a new game mode, new combat mechanics for new playable characters, and new costumes that will be compatible with in-game cutscenes.
The new game mode is the "Legendary Dark Knight Mode" and it has nothing to do with Batman, but everything to do with a "tremendous" amount of enemies. This game mode will pit you against tons of enemies, a mode that had every intention of being in the PS3 version, but never made it in.
For the first time you will be able to play as Vergil, Lady and Trish in Devil May Cry 4. Each character will have a unique fighting style. Vergil's style introduces the "Concentration Mechanic." As Vergil fights, his attacks become stronger the more calmly and flawlessly he fights. He will utilize the "Grim Trick" ability which will allow him to teleport.
Lady is a long-ranged fighter who emphasizes on firearms and Trish won't be switching weapons in the game, but will instead use the Sparda sword.
[PS]