I doing a search on amazon for conan game products and the list three class books coming out next year. They are Conan:barbarians, borderers,nomads for May. Conan:Nobles,Scholars,soldiers for July. And Conanirates,thieves,temptresses for August. 8)
To be honest, I'm not very excited about these products (and this is the first time for this line). Titles suggest a collection of feats and prestige class, and I think Conan rpg doesn't need them. Actual customization is enough to (greatly) shape any concept you have; more options, for me, are a dangerous temptation for the min-max gamer that is inside each of us. And I don't like the idea to have too many rule books. It makes difficult to remember where a specific rule is listed; making a character becomes a pain, as solving rules problems during a session (D&D 3.5 with Complete X, Races of Y and 'environment' Z docet!). I'd prefer campaign specific products, definitely.
As far as class books, I'm OK with it as long as these are IT. I think it's good for the players to have a few more options to tailor their characters. However, I understand your concern of D&D like volumes of rules. It's getting tough already with Feats scattered throughout all the books. I'd hate to have to have specific issues of S&P, a certain online article, and several different books, just to understand what a character has going on.
Several players in my group have felt the Corebook isn't really suited to them as it's mostly GM rules and such. These books will allow those players of mine to sink thier teeth into something 'their own'.