Well, today is release day. I had already pre-ordered at Best Buy cause reward wise, it appeared to be the best. What I have seen so far is :
Portal owner pack (comes with game and tree giant) (Best buy has a backpack with poster, bracelet, keychain, and stickers for pre-order of either pack)
Game pack (comes with full game set and 2 small characters, tree giant)
Series 2 characters : game 1 characters with new look and available new options
Giants : Crusher, Bouncer, and Swarm (Target has an exclusive Crusher called Granite Crusher)
3 pack comes with a cannon an older character and a new one (shroomboom) (Gamestop has an exclusive gold cannon)
New characters : Chill, Pop Fizz, and Fright Rider.
So far, price wise, portal pack 59.99, game pack 74.99, original size characters 8.99, giants 14.99, and 3 pack is 24.99
Game is pretty neat. Chests/hat boxes open a different way, experience bar is easier to read, gold is more available. Difficulty settings are optional now. There is a new type of treasure called a luck o tron. Giants have the ability to do new stuff (break through floors, do feats of strength, etc). All-in-all, its definitely impressive if you liked the original game.