Ahh this takes me back to before the UU started suckingARRRGG!!
You know what's weird Bendis often does better revamping 616 B-list villlains than he did with ultimate B-list villains. He can make Purple Man scary in the 616 universe, but makes Ultimate Scorpion and Ultimate Vulture are throwaway villains? WTF!
It seems DC is better at this than Marvel, if Gail Simone can make Cat Man cool, there should be no limit on making lame villains cool.
anyway, I guess I will start, you know who I think should be more of a threat, the Mad thinker. Here me out, this is a guy who can predict almost anything and he has a mind like a super computer, he can pose a intellectual threat to Reed Richards that is different from Doom's (unlike the Wizard, who comes off as a fifth rate Doom wannabe). This is guy who could hack into SHIELD database and get the SHRA list, get almost any information on the planet and sell it, use his networking skills to cooridate super villain attacks, etc. Mad thinker could make Oracle look like a 5 year old playing with her dad's spell n' speak. This is the guy who could engineer a stock market crash with little effort Considering that Reed Richards went to him to double check his finding, he should be in the perfect position to corrupt the SHRA.
I also think Trapster should can his gimmick from glue guns to death traps, but I'm not sure how that change would made.
Anyway please pitch your ideas on revamping villains B-list or lower in the 616 universe.