So... basically on PBE, Runic Echoes has been changed to basically be Enchantment: Magus w/ Mana.

Enchantment: Magus gave 20% Cooldown Reduction & 80 AP. This Enchantment gives 20% Cooldown Reduction, 65 AP, and 300 Mana.

Well... I guess this means 'Welcome back Magus?'

EDIT: In my tests, it seems like the Luden's Proc is gone, so it's literally a stat stick now (not counting the stats it gets from Stalker's Blade/Skirmisher's Sabre)