Of course, let me rephrase.
I doubt there will be any that are as successful as what we have already had. Once they have finished the full run to Avengers, they can't hang their hat on making movies that merely "Avengers 0.5". They can't use that mold, and we can't use that excuse.
Unless they simply start building towards Avengers 2; which would make all the sequels to the individual movies nothing more than "Avenger 1.5", and how long can that possibly stay fresh?
Either way, this is nothing more than discussion for discussion sake at this point, which isn't a bad thing. These movies are going to be cool, even if they suck. Sort of like pizza