58 kegs:
16 epic cards (4 of which are premium).
4 legendary cards.
^there would be even more premium silvers, but I got to choose between cards that I don't own and premium versions of what I just got from previous kegs. Lots of common and rare premiums as well.
Wait wait, what? So I guess i was prettly luck. I've opened 10 packs (got late on the Closed Beta) and got 6 legendaries (the golden ones with a golden square are legendaries, right?)