Blizzard won't be suing anyone for this. All they would do is generate a lot of negative publicity and come across as raging assholes.
But if the guy spent the next year building this thing and then wanted to sell it for $5.00 a pop would you rage out on him if he did?
I wouldn't.
If this would be EA, they would probably sue unless you have their blessings similarly with
renegade x(Command and Conquer that EA has rights has given them blessings) . I don't know about Activision/Blizzard's policies though. I just revived the thread because Swen have stated this on the latest article of gamespot for D:OS.