Andreas Constantinou at Vision Mobile, a London-based advisory and research consultancy, put together a nice review of the various App Store state of affairs - and it's well worth a read. Unfortunately, he doesn't have data yet for Google or RIM, but the Apple vs BREW comparison is interesting. I hadn't thought of Qualcomm as contender for this, but it is true, the BREW system was an early attempt to solve discovery and distribution problems for mobile consumables. I have my doubts about it's future though since one, it's engineered specifically for mobile operator controled billing with bias towards the fat head; and two, it lacks the BI trending and usage modelling power that other systems are introducing. Which leads me to my next thought... how much longer will it be before Amazon enters this game, or will someone get wise and approach them directly with an aggregated 'apps-for-smartphones' portfolio offering?