The preview reveals that when Garona (who has the same tailor as Valeera Sanguinar apparently) killed King Llane, she was actually pregnant. When she 'disappeared' from the overall Warcraft story, she handed off her child to the Undead Mage/Warlock/Necromancer Meryl for safekeeping since she couldn't trust herself while she went to deal with her inner demons. It's interesting to note that this Undead Necromancer isn't actually a member of the Forsaken, so that Forsaken Warlock action figure you may have purchased awhile back isn't a Forsaken at all. He predates Ner'zhul by quite a bit, and the comic describes him as being undead via his own will and sorcery. He should prove to be a pretty neat character.
I have to be honest though, I probably won't see him become a neat character. I stopped reading the Warcraft comic a few issues ago, because I find the writing horrible. I very much enjoy what they've done with the lore in the World of Warcraft itself and I like the concept of utilizing an expanded universe of books, comics, whatever else to further the lore of the world, but the writing in these things is just unenjoyable. The art is often criticized as being too anime (Darion Mograine in the Ashbringer series is basically Cloud Strife) but the art is actually something I like about the comics. The writing is what gets me. I even like the character of Varian Wrynn in WoW itself, I like the controversy around him and all, but I couldn't bear to read his dialogue in the comic book. Aaand that's enough of that rant, I think.
Garona's child is described as being the savior of Azeroth in an unearthed propecy, and as corny as that whole spiel sounds, I suppose I can't say it's out of line with Warcraft lore. There's plenty of prophecy and immensely powerful beings in Warcraft, the easiest example being Medivh, who I'm sure will play a role in this arc. Garona's story weaves in with his own, so it wouldn't surprise me if that child belongs to Medivh (or Medivh's former parasite Sargeras). Garona herself was retconned from being half-Human to being half-Draenei, so that would make the child... Half Human, quarter Draenei, quarter Orc? Is that how that works? Unless they decided the retcon was a bad idea, and she's Medivh's daughter to begin with, making her son his grandson.
Man, who knows. I'll probably keep an eye on this arc via Wowwiki and other sources, but I won't be spending money on it.