One thing that would be awesome is if they brought some other franchises into the MCU, such as Blade - who can't be played by anyone other than Wesley Snipes in my opinion.
Plus Elektra who is played by Jennifer Garner, Daredevil... Who could have someone else replace Ben Affleck and of course Men In Black.
Marvel is massive, allot of people don't realise that Marvel films actually predate Iron Man. :P
Daredevil and Elektra are already in the MCU, theyre on Netflix.
The TV and Movies are not going to mix into each other to any great extent except for a few cameo's here and there.
Plus, Elektra just isn't the same without Jennifer Garner.
It's also the same with DC, where they have different Superman actors in the Supergirl show and Superman movies... And different actors for Flash.