That's right...we don't even have Light of Destruction here in the US yet, and Japan has a brand-new set.
There are 2 new monster Supertypes: Tuner and Synchro (I say 'Supertype' because this classification is the same kind of classification as Toon or Spirit). Unlike other Supertypes, Tuner and Synchro monsters are not automatically also considered Effect monsters; there are Normal Tuner and Synchro monsters. Synchro monsters are placed with your Fusion monsters in your Extra Deck (this is a name change; it used to be called the Fusion Deck). The name name comes with a new rule: there can be no more than 15 cards in your Extra Deck.
We also have a new kind of Summoning known as Synchro Summon. This is a sort of blend of Fusion and Ritual Summon. To start, you need 1 Tuner monster and 1 or more non-Tuner monsters on the field (unlike a Fusion or Ritual Summon, you cannot use cards from your hand). Then you can select a Synchro monster in your Extra Deck. If you have the correct monsters on the field and their combined Levels are equal to the Synchro monster's Level, you can send those monsters to the Graveyard and Synchro Summon the Synchro monster (this is also considered a Special Summon). It would make sense that sending the monsters to the Graveyard is a cost, but I have not heard a decisive ruling on this yet. It has been ruled, however, that the monsters do not need to end up in the Graveyard; if an active effect forces them to go elsewhere, you can still perform the Summon.
There is a new monster Type (along the lines of Pyro, Winged Beast, etc.): Psychic-Type. These are used by a new anime character named Aki, who has not yet been introduced. An interesting side note: this set does combine the above two strategies, producing Psychic - Tuner monsters and Psychic - Synchro monsters.
Finally, there are some term changes. What these will be changed to in English, or even whether they will be changed at all in English, is not yet know, but here they are in Japan:
Tribute -> Release
Tribute Summon -> Advance Summon
Fusion Deck -> Extra Deck
Keep in mind the old terms are interchangeable with their new forms, much like 'Magic' cards and 'Spell' cards. Effects that apply to Tributing a monster apply to Releasing it as well, and vice versa, etc.
One more thing: your Side Deck can now contain any number of cards between 0 and 15. Before, you had to have 15 or none at all.
Well, enough small talk. Here come the new cards!