The Shadow
Hero
Classes that IMO are almost sure to be there (and should):
Ranger
Paladin
Bard
You forgot the Druid. But yes, I expect to see all of those.
Classes that I expect to see, and really hope make the cut (as classes):
Monk
Barbarian
I have to say that I just don't 'get' the Barbarian as a 5e class. Berserking strikes me as a specialty (and possibly a fighting style) much more than a class, and if you take that out, what are you left with? A fighter with a certain cultural background. Oh look, we have backgrounds already.
The monk is just plain strange in many respects. I expect it will probably be in, for tradition's sake, but it really is the odd man out among classes.
Classes that I don't expect to see but would be a pleasant surprise:
Psion (it's almost a D&D tradition NOT to put them in the first PHB)
Warlord? (would also be a kickass specialty)
Some kind of non-Vancian divine caster (preferably with an entirely unique spell system, not just "cleric spells with spellpoints")
I really don't expect to see the Psion. It's traditional, as you say, and there's only so much page count to go around.
I think Warlord could indeed make a great specialty. I think it 'feels' more like that than a 5e class.
Non-Vancian divine: Yes please. I really like the 5e cleric thus far, but some options in the divine realm would be nice. A divine version of the sorcerer is very easy to imagine - instead of a bloodline, they start to resemble their god. A divine warlock is a little harder to picture, but perhaps a shaman?
Classes I only expect to see as specialties/arcane traditions/etc:
Illusionist (pretty clearly a wizard "arcane tradition" IMO)
Assassin (either a rogue scheme or a specialty)
Definitely agreed about the assassin. I'm thinking it could be both a specialty AND a rogue scheme. Add in the Spy background for additional fun!
I'm very eager to find out how wizard traditions work. Depending on how sweeping they are, the Illusionist might well fit in there. But what I do not want to see is a retread of 2e and 3e specialists, who merely get a bonus with one school of spells and bar others. The 1e Illusionist was much more interesting than that!
Something like a cleric Domain could maybe work. Though I think even Domains could be made a bit more sweeping - I wouldn't mind making them more like 2e Spheres.