Don't max out wisdom. Calculations have been made about the wisdom skill, and it simply isn't worth getting it. The wisdom skill might get you an extra level or two at the end of the game. Raze knows the details.
But saving skillpoints can come in handy, since most skills are only available at certain levels. Especially in the beginning, you shouldn't waste skillpoints on skills you don't really need. Saving up skillpoints is indeed handy.