Blizz "3rd Team" title upcoming..

I just wanted to see if an idea for a hybrid was possible, that's all.

I didn't get that from your response, but okay. It would take a serious Lore stretch for both universes as the origins of the Burning Legion are somewhat well explained, integration into Diablo's universe would be hideous.

However, Starcraft by it's very nature would be easily written into either storyline due to the whole space thing, but if any race found itself in conflict with the worlds of Diablo/Warcraft, the conflict would be over in such a one-sided manner that it wouldn't be worth writing about. Although it could be an interesting conjecture from the Low-Tech POV as to what might happen if the Earth were contacted by an advanced, spacefaring civilization, but I think an entirely seperate game would better suffice for that kind of exploration.

TLDR; Warcraft + Diablo = unlikely and Starcraft + Anything = easier in some respects, but strains your suspension of disbelief a lot.