Good move in some respects. It will help users try out the app before paying any money and it may help developers drive more sales. OTH we need to see whether

Good move in some respects. It will help users try out the app before paying any money and it may help developers drive more sales. OTH we need to see whether (as mrshoe said) whether "Free" becomes the new $0.99 and if this has adverse consequences (for developers in terms of sales and for users in terms of app quality). If the app is free, it will be easier for people to write fake reviews critical of the app. I don't see any risk of "bait and switch" apps because no one is going to take the upsell if they are unhappy with the app.