no, it says you can also choose a lower level power, on the power entry o page 28, I believe. I think it' also valid for wizards, as the spellbook class feature simply allows you to know one more power per level.
What I mean is: aside from the line in the spellbook entry that says you can prepare one of two dailies at first level, when you only have one daily per day anyway, is there a line somewhere that explicits that you can't choose to prepare your spells regardless of their level? Like, you have four spells known, and two spells per day, and you can prepare whichever spells you choose in those "slots"?
I'm not trying to find an exploitable way to read a rule. It's just that I didn't find the rule stated clearly. Am i the only one who sees this as confusing?