I just started to create a wizard but canceled it after i found out i have to invest all 28 skill points (in two class skills from wich only one has any use, concentration) the rest have to be blasted in skills with double costs. That actually means the advantage of the many skillpoints (for multiclassing) for wizards is mostly negated.
So i suggest that at least the bonus skillpoints from intelligence can be saved to later level-ups.