Particle_Man
Explorer
It's interesting that although the list is only 1 longer (<10%) than the PHB set, 75% of it is from elsewhere. How might the differences be characterized? Does this reflect some common theme, a distinctive kind of setting, more or less spell-casting, style of play, some particular fictional referent?
Since the first questions were answered, I will try to answer some of the rest.
The Knight I explained earlier, a Tank that can avoid the problem of monsters just avoiding him!
The Warblade is a fighter that can use maneuvers, some flashier than others, that lets them remain competitive at high levels.
The Swordsage is similarly a better version of the monk. It also uses special maneuvers.
The Crusader is a sort of Knight. It also uses special maneuvers. Can't grab people like the Knight, but harder to kill. Has a religious focus. Subs in well for the paladin.
The Scout is a cross between the ranger and the rogue, and can sub for both.
The Factotum I mentioned earlier. I left the bard in because the bard is a better face and party buffer. The Factotum is the jack of all trades nerd, who studies a little of everything. Like Cliff Clavin from Cheers but actually useful.

Duskblade - a fighter type with full BAB, arcane spells, and the ability to cast spells through his weapon while attacking with it. Nice mix. Elven flavour.
Beguiler - lots of illusions and enchantments, lots of roguish skills. Thus a good illusionist/thief.
Warlock - has spell-like abilities, usable at will, all day long. Yet it is not overpowered (arguably, at higher levels it is underpowered, but the ability to build magic items without knowing the prerequisite spells can mitigate that). It is much easier to prep a high level Warlock villain than a high level Wizard villain, if one is a DM. And with no slots, spell points, uses per day, etc., to keep track of, it is great for players that don't want to worry about that stuff and just want to zap things with magical energy.
Hope that helps.