Badboy -
Not so fast. The "Adam" and "Eve" identified by geneticists were the most recent common male ancestor and common female ancestor, not to only or the earliest. If genetic Eve came later, than genetic Adam's only wife (or if he had more than one, his mother) would be a common female ancestor for all of us, just not the most recent.
Say Jack marries a woman, has children, divorces her, and then marries her cousin, who shares a grandfather and grandmother. A child of the first marriage and a child of the second would be related like this, barring further complications: Their most recent common male ancestor would be Jack, and their most recent common female ancestor would be their mothers' grandmother. But the grandmother of the childrens' mothers would be married to another common male ancestor - the grandfather of their mothers. If the family tree had branched as much as possible, this would have been their most recent common male ancestor given that their mothers were cousins, but sometimes the branches cross, as with ex-wife's-cousin-marrying Jack.
This is what the geneticists were looking for - the most recent common male ancestor, and the most recent common female ancestor, that they could trace based on the Y-chromosome for males and Mitochondrial DNA for females. Genetic Adam, coming before genetic Eve and being forefather to all of us, necessarily identifies a common foremother: His only wife, if he had only one, or his mother. But since the father-provided Y-chromosome traces back much further than genetic Eve's time, which is identified by Mitochondrial DNA passed on only by the mother, apparently genetic Eve was not a one-guy sort of lass.