So either Reed or Nick Fury are still the favorite choices, eh?
Techno is possible, but could Techno have "pulled strings" for Osborn before? Now while that statement alludes to Reed (or Tony, although it makes little sense for Tony to sabutage his own plan), Nick Fury also was able to make up fake identities for several of the Secret Avengers in CW #2, including jobs. They're using safe houses that he knows about. Fury is rogue but he still has some pull. And if Fury could have given Cap an "Anti-Iron Man Spray" sort of chip in CW #3, then a serum to release Osborn from nano-control wouldn't be a biggie.
Pietro's a nice theory, but I don't see him having the know-how to cobble together a serum like that, nor do I see why he would help Osborn, who isn't a mutant. He seems fixated on only helping to repower mutants of late. I also still am not as eager to call his actions during HOM as outright evil like Marvel is. I wish all bad people wanted to make all our dreams come true and make us happy like Pietro did to get what they wanted. He easily could have had Wanda fashion some post-Apocalyptic slaveword where humans toiled naked in chains breaking rocks and mutants all lived like Kim Jong Il in North Korea. He didn't. But HOM and it's lackings is another story.
I liked the Nick Fury theory. My gut said Reed, but it's been wrong before. I'd probably prefer it to be Fury because Reed already has too many character-assassinating actions in CIVIL WAR without needing to add "aiding a known violent felon" to them. Nick Fury, on the other hand, has done plenty of morally questionable things to "get things done", especially in the last few years when 616's sought to copy Ultimate's version of SHIELD.