Well, mattc, this was very skilful timing, releasing this interview just as we were starting to lay into Don's credentials and suitability for the FF! 
Having said that, he comes across well in the interview. It's sad that some of the worst stuff (Thing's burping, the 'spin' line) was added later and is nothing to do with him. I also wasn't keen on Sue's disguising her zit (it might have showed a subtle use of powers and we all know about blemishes popping up when you least need them!)... but it seemed a bit light and fluffy (much like Storm and Beast commenting on each other's hairdo in X3).
As for the next movie, it has to be Inhumans (possibly with Franklin or Annihilus tied in). Whichever villains or other characters are chosen have to relate to the thematics of the FF. Moleman has nothing to offer, he just burrows in the ground; Puppet Master could come off as a silly voodoo thing; Skrulls are not a good idea.
Inhumans work because they are the opposite of FF - Inhumans choose to be mutated (by the Terrigen Mists) and embrace their unique difference, they choose to live in secrecy away from the spotlight; whereas FF were changed by accident (and are still dealing with that) and at least one of the FF (Torch) revels in fame or celebrity, while the others have to try to deal with the spotlight being shone on them all the timet. Inhumans provide a contrast to the FF which could see Torch maturing (and falling in love with Crystal) and the others learning lessons too. They just might have to miss out Lockjaw, who is essentially a giant bulldog with a TV aerial on his head (and would only lead to critics hating it, especially if we had Torch jokes 'Say Lockjaw, can you get the Discovery channel on that.' or 'Can you retune so we can get a traffic update.')
