Revised predictions:
Barbarian: In (mentioned in some article somewhere, although as a point in an analogy & not a playtest blog).
Bard: Some features blended into Marshall to make the Warlord, but mostly gone (at least in the 'roguish minstrel jack-of-all-trades' conceptualization). This saddens me.

Cleric: In, duh.
Druid: Still no mention. I'm leaning toward gone & folded into cleric despite my earlier thoughts about the complexity of druid class features warranting a separate class. We'll see.
Fighter: Confirmed in from multiple sources.
Monk: I'm betting out, with an unarmed combatant tree for fighters.
Paladin: In (assuming the playtester running one is not speaking about a PrC, which doesn't seem to be the case).
Ranger: In from multiple sources, none of which appear to be referencing a PrC.
Rogue: In I assume.
Sorceror: In? At least not folded into Wizard according to one source.
Wizard: In from multiple sources.
New core classes:
Warlord: Seen on the laptop screen in one of the preview videos. My pure conjecture is that this is a marshall-type character with some bardy stuff added into the effects it can produce.
Warlock: One mention only. Seems odd to have Sorc & Warlock & Wiz. Perhaps Sorc is folded into Warlock (leaving the 'sorcs & wizards are not merged' comment true without revealing the true fate of the sorc).
With 2 new classes & the statement that the number of core classes is less than the current 11, a minimum of 3 have to be dropped. My bets are on monk, druid, & bard (*sob*), although other possibilities still exist: sorc folding into warlock, some named 'class' actually being a PrC, barbarian as a fighter tree (& the use of it in an analogy being a poor choice), or (extreme longshot) rogue as a tree of fighter or ranger.