For now Marvel is still using Diamond Distributors but they are on the verge of ending that deal. DC already switched distributors from Diamond Distributors to Lunar last year. Diamond Distributors is losing their lock on a lot of companies. IIRC Marvel will be switching to PenguinRandom House in October but for now the agreement is still with Diamond Distributors
Diamond Distributors rankings for July haven't been published yet but here are the June figures
The Comichron site keeps track of these figures also, gathering data from the distributors and here's what they have from June and it looks like they might be combining data from other distributors than Diamond, which is necessary now since they aren't the only game in town anymore.