Cavalier- D&D has long had a love affair with this concept, but it never seems to work. Perhaps the Knight in the PHB2. However, this is a second martial defender, and would really just be redundant next to the Fighter class at the moment. Again, we are trying to show love for the fighter, not outdo him in the first supplement. Aside from being a paladin without the magic, I really can't see anything that this class could do that the fighter couldn't, except perhaps as a class based on horseback fighting.
Archer- Lots of players seek the Archer archetype, so it stands to reason that this could be a class of its own, except that it is probably stepping on the toes of the Ranger, who tries to occupy both the Bow-User and Two-Weapon-Fighter archetypes... Again, we are trying to show love to the new classes, rather than overshadow them.
Alchemist- I love the idea of an alchemist class. I think ever since I saw the alchemist in Exodus Ultima I wanted to see an alchemist class in D&D. (not to say the alchemist in Exodus was a terribly good class... It was basically half the strength of the wizard. But it seemed like a cool idea...) I often try to play to that archetype myself. BUT, I don't think it qualifies as a martial class. To me, an alchemist is someone who is both a primitive scientist and a magician. He excels at brewing potions and tossing explosives, and even perhaps an inventor. Even if you take away the magical portion of it, and leave it as a primitive scientist, the alchemist still isn't what I would call a martial class. Nonmagical, yes, but martial, no.
I don't know... going over it, I really expect these first books to be more like the sword & fist/tome & blood/etc. run of books than the later "complete" series... books to build on the classes in the PHB, rather than an introduction for new classes.
