The cleaned up warlord article contained some information that might have been easily missed:
I am hoping that there will be rules to mix and match a few class features between class sub-builds (ie Wizard and Mage). I'm not totally sure that will be included in what is mentioned in the above quote. It could just mean multiclass feats when it says "ways to gain some of the class features". Either way, I'll be looking forward to reading this article.Included in the Class Compendium series (in April) is an installment on feats to round out your character. For the most part, the feats included in Class Compendium are intended to provide characters built using the Essentials rulebooks with more options for using the Player’s Handbook material, as well as providing characters built using Class Compendium with ways to gain some of the class features presented in Heroes of the Fallen Lands. (Link)