This thread has lots of comments that really sadden me...

So many people are thinking of races and classes only in terms of power, like "Class X should be axed, they're weak". Well if a class is weak maybe it should deserve to be made better isn't it?
If they are putting any grain of salt into class set design, they are choosing what is "in" and what is "out" based on (1) if the concept of the class is basic enough and allows room for customization ["Mage" is a much better concept for a base class than "Beguiler" or "Spellthief"], and (2) if the mechanic of the class is unique enough to make playing it a different experience [as it was between Wizards and Sorcerers in 3.x, even if the concept difference was minimal]. AFTER THAT they would make sure all classes are balanced with each other.
So what traditional classes might be axed?
Paladins: the concept of holy warrior is strong, but so is strong the idea in many gamers that it should be something special. NO CHANCE that 4e won't have paladins, but it is certainly possible that a PC would need to be high level to become one. Axe chance: 50%.
Rangers: the original Tolkien concept is certainly special and could face the same fate as the paladin. HOWEVER the Tolkien concept has been long gone since 3.5, when rangers become just "outdoor light warriors", which isn't prestigious at all. It could be merged into a single fighter-type class, but I don't think the chances are that high. Instead, good chances that the class is simply renamed to something more generic, like Scout. Axe chance: 20%.
Barbarians: tough call... could definitely be integrated into the generic warrior class, but it's possible that some new unique mechanics still justify this as a separate class. Axe chance: 30%.
Bards: very narrow concept for a base class, very few unique abilities (bardic music the only class-specific mechanic). Since multiclassing is certainly going to be possible in 4e, this base class has high risk of being removed. Of course, it will resurface in one of the earliest supplements as a mid/high-level option. Axe chance: 90%.
Monks: cool concept but for many not quite fitting with the clear western style of D&D. A martial artist could easily be seen as a kind of fighter, thus rolled into the fighter class. However, martial arts are too cool not to deserve their own mechanics, so most probably the Monk class will come back later in an oriental supplement (and perhaps be split into more classes). Axe chance: 80%.
Fighter: the concept is absolutely essential to the game. However the 3.x fighter is widely regarded as the most "generic" class of the bunch, which might mean that they decide to split the class into 2-3 more narrow but still wide concepts (melee fighter? archer? war leader?). Axe chance: 0%. Split chance: 50%.
Cleric: essential concept once again... We could see new divine casters (shamans?) but the basic priest is gonna stay. Axe chance: 0%.
Druid: very strong concept, theoretically could be a specific cleric but usually there are too many signature abilities that it probably deserves an own class. Making them "cherry-pickable" abilities is possible but seems to ma that a nature priest would almost always end up taking many of them, and a non-nature priest taking nearly none. Also possible to make Druids a high-level option, but how are they going to fill the earlier levels? (none of the other concepts serves well as prerequisites for being a druid). Axe chance: 5%.
Wizard/Sorcerer/Warlock: another essential concept to the game. However the arcane classes as a whole see a split due to different mechanics (and a minimal difference in concept just to justify the division a bit further). Mechanics are gonna change at least somewhat, since we already know there will be "recharge mechanics", it remains to see how many different of them will be, as this will probably set the number of core arcane classes. I bet that then NAMES chosen will depend on popularity in 3.x so my guess is no class named Sorcerer and definitely a class named Warlock (but this is just about the naming, not about the concept). Axe chance 0%.
Split/merge chance: 100%.
Rogue: this is a very traditional and cool concept, but "being roguish" could indeed be implemented as a series of feats/talents to apply to any other class. Personally I think tradition is going to win in this case. Axe chance: 5%.
My bet? 10 classes:
Fighter class1
Fighter class2
Fighter class3
Ranger/Scout class
Rogue
Cleric
Druid
Mage class1
Mage class2
(insert new 3rd divine caster or 3rd arcane caster here)
Which in fact is just about the same layout we had in the last 2 editions...
