So the invoker looks like an improved wizard.
The sorcerer looks like a much improved warlock.
Chaos bolt is basically eldritch blast level damage (slightly higher for the obvious build choice, actually, because +Dex should beat 1d6) with a whole extra cleave-like feature for dealing extra damage to other targets added on. Oh, and it attacks Will. A huge increase in damage output.
Fairest comparison for dailies:
They both have a level 1 daily that targets reflex, does 3d10+Main Stat damage. The sorcerer gets +Dex damage, and the warlock gets +1d6. The warlock and sorcerer also get a secondary effect of roughly equal value to 5 ongoing damage (random for sorc, definitely that for warlock). So the sorcerer does fractionally more damage without having to curse first, but at the cost of some randomness. Very close. But the sorcerer does extra damage on a miss. Outright better.
Or look at the level 1 daily that does 6d6+Cha+Dex damage along with a 50% chance of a very decent debuff. And it attacks Will.
I hope this is deliberate, and that the warlock will receive a parity-inducing boost in Arcane Power.