I realized that discounts now are in “Catalog–>Promotions” but I could not make it working. I assigned different discounts (category, membership) but they were not counted though, at my thought, all conditions were correct. Anybody check it?

In beta-2 as it was told discount (it is called promotion) system is working. I was playing with it a little bit and found it very powerful and flexible. Now it is possible to assign discounts to a single customer, plus free shipping (in old version I could do it only for group of users), plus free products. Thank you, developer guys!