This has been raised before but as we now know what is rounding out Phase 1 of the MC release schedule I thought I'd put up another round of speculation.
To kick off, before the X-Men and Fantastic Four villains and heroes start to take over the next runs I would like to see:
Red Skull - in some ways the quintissential villain. There are no good things about Oberfuhrer Johann Schmidt. Even Dr Doom and Loki have fought with the good guys when it suits them but Red Skull is purely for himself and his goals which are self centred. There really are no good points with this gentleman. He taps into HYDRA of course as well mad science (eg. Cosmic Cube, robotics etc). He has encountered the Avengers and X-Men (going to the length of stealing part of Professor X's brain). He has been featured on the cards already and as implied should be a scheme strong villain with loads of minions that really challenges the heroes. Side schemes should put pressure and distract the heroes from focusing on getting to the Skull (I can see some synergies with the Green Goblin scenarios here but dialed up even more.
Dracula- I'm an admitted vampire fan and I do like Dracula when he appears. He has fought Blade, Dr Strange, Thor, the Avengers, Excalibur and the X-Men on a number of occasions. Another minion and scheme heavy villain he is also a powerful fighter in his own right when he's powered up by one means or another. I think he'd be perfect for a Halloween release and a nice double with Blade if he is released this year. A Dracula scenario may not even start with Ol' Fang but as a local cult of Darkholders who are seeking the Darkhold for their master which develops as the plot progresses to a vampire outbreak culminating in a titanic struggle against a powered up Lord of Vampires with the fate of the human and vampire races at stake (pardon the pun).
Over to you.