You didn't think just because Blizzard released a beta of Diablo III
that what you played was finalized and they're just doing bug fixed did you? Of course not! Blizzard has listed a bunch of things
that are being changed and removed as we speak!
It's a pretty long read so I won't go into the entire detail of what's coming and going, but there are some biggies. The Mystic Artisan is going bye bye, but she might be back later. Also going bye bye are the Cauldron of Jordan and the Nephalem Cube. With the town portal being back into the game, these two were deemed unnecessary and detracted from making you go back to the town.
Remember how you had to carry a bunch of identify scrolls? No, you don't need those anymore as your character can identify items now with a right click of a button. I guess Deckard Cain can take a vacation from looking at magical items in the third game.
Defense, Attack, and Precision attributes have been kicked to the side leaving just Strength Dexterity, Intellect, and Vitality. The post linked will go into more detail what that means and how it affects some classes.
There are a bunch of other changes going in and all in all, there's some major things still being worked on before the game can be shipped. Let's hope it's not too much longer though.