I believe what people are complaining about is the lack of a sort of "passive" use for intelligence. Strength modifies to hit and damage rolls with melee weapons, dexterity modifies ranged weapons, constitution gets both the entire score added to your hit points and modifies your healing surges, etc.
Intelligence used to be sort of the odd-ball out amongst the mental stats, since it would modify something (2nd ed. had Wisdom modifying your saving throws against mental effects and charisma determining followers, whilst 3rd edition cut any passive effects of Charisma and Wisdom adjusted your will save).
Intelligence meanwhile has always had some effect, but if we're moving back towards a model closer to earlier editions, I wouldn't be surprised if Intelligence only effected several skills and your languages known.