Weird. Why is is that the 1d6 per caster level on a fireball seems to me to be the sacredest of all cows, the most D&D thing about D&D?
That said, if they are changing this to a different scaling system (ie, there will be more levels of spells, but those spells will scale more slowly) then this seems to support the theory that it will be lower level spells (taken relatively) that will be cast at will/without preparation, etc.... If the spells don't scale as much, there is less danger in this being overpowered.
Example: 3rd level wizard prepares spells pretty much as in current system, and has 1st, 2nd, and 3rd level spells (if there are going to be 25 levels of them now).
He'll get (for example) two 3rd, three 2nd, and four 1st, and five 0 level spells per day.
In addition, he'll choose one of his second level spells that will automatically be castable once per encounter (above and beyond the prepared ones).
In addition, he'll choose one of his first level spells that will automatically be castable at will (again, above and beyond the prepared ones). Probably a cantrip or two as well by by this point.
In a system like this, spell selection and preparation decisions are still difficult, and conservation of your best spells is still important, but a wizard would never run out of things to do. He'll always have, say, one Scorching Ray and unlimited Magic Missiles, but a magic missile might do 1d6+(1/caster level), scaling more slowly then it does now. (We might be seeing first level wizards with one cantrip that they can cast at will, so you'll always have a Ray of Frost or a Daze, or whichever one you choose)
This is all clearly speculation, and is almost assuredly wrong, but it would seem to be one possible interpretation of what we know so far...