I actually enjoy not having more rules content released. Adding new or different rules for the sake of book sales gets old. I'd kind of like to see the old 1990's Boxed Sets revisited, though. Three full-campaign adventures so far is kind of neat, but their kind of spotty on the quality and actual content, not to mention the constant focus on FR is getting a bit old. I'd love to see some variety.
Or give us some smaller books that, instead of going from 1-15+ are meant to span 4 or 5 levels. I honestly expected more of this based on the "Tiers of Play" section in the PHB. Unfortunately, it's looking like the intention is to release licensed campaigns that are designed with organized seasonal play in mind.