I'm hoping WotC will create a middle class for those of us who <INSERT POLITICAL OPINION HERE>
Honestly, I'm not big on the need for new classes. A lot of things can be subclasses. A lot of things are already classes, or are really modules trying to ride in the class chassis (we don't need a warlord who can heal, we need an "inspirational hit point" module that lets anyone with a CHA scream your friends back to consciousness!; psionics isn't a class, it's an alternate magic system!; etc.), or are just a spell or two away (seriously, an EK is a swordmage, and if what you're missing is the mechanics of greenflame blade and swordburst, those are just spells). Classes aren't the appropriate container for a lot of these things in 5e, even if they were classes in the past.
If WotC is going to create any class, I hope they do not create a class based on weapon/armor/skill proficiencies, alternate spell lists, or narrow mechanical tricks, and stick to making classes with unique stories and character arcs.