The website suggest there will be 8 heroes. The one's I've been hearing are the Witch Hunter, a wood elf style elf, an ogre, a kharadron dwarf, some kind of similar to Bret paladin, and a wizard lady of some kind (possibly fire). The remaining two is still a mystery.
But I am stoked to see this as a weekly feature. Looking forward to more info, and hopefully this means its coming soonish. April seems like the current bet.