Neonchameleon
Legend
4E was a bit of an aberration where it comes to DnD; it tried to enforce a few roles that, realistically, had not existed before. Other roles were forced to act in ways that sometimes did not quite match to DnD norm.
Correction: 3.0 was a departure from D&D tradition by not having roles for the classes. 4e was a return to that tradition only making the game more flexible and the roles looser than in any edition prior to 3.0.
If you read the 2e PHB there are explicitly four roles spelled out. Fighter (Fighter/Paladin/Ranger), Rogue (Thief/Bard), Cleric (Cleric/Druid), Wizard (Generalist/Specilist). The PHB is very clear on this. The 1e Monk by the way was a variant Thief with almost exactly the same strengths and weaknesses and just some Sfx tacked on.
The innovation 4e made was in separating role from power source so a Warlord could do most of the job of a Cleric.
Beyond that, it entirely depends on party tactics; some parties work very well with a lot of fighters, some depend more on having a lot of access to magic. Different people may give different ideas of roles and what roles exist, but that depends on which theory they approach the game with. Ultimately, the old standard of fighter, wizard, cleric, rogue can cover things pretty nicely.
The old standard of fighter, wizard, cleric, thief was made explicit in the 2e rulebook. 4e roles were based round those roles in the 2e rulebook but less strongly coded so e.g. your damage dealer did not need to be martial.
Edit [MENTION=98938]DeF[/MENTION]CON1 I await the appearance of the Warlord class so you can make a fighter-type able to keep the party going.