There are many myths around the apps world and, since Angry Birds became a global phenomena, there is a real gold rush pursuing Roxio's success among developers. I actually met some of Roxio's original employees back in 2002-2003 in my former professional life. They were just a second tier supplier of java games with a narrow portfolio, trying to squeeze in carrier wap storefronts, tight walled garden space at that time.
In today's mobile world it's all about platforms, and for developers (unless they do it for non profit or personal entertainment) it's all about coding and porting for a platform, getting visibility on platform storefront, making a minimum number of downloads, in-app purchases or ad hits, and the associated revenue share they consequently will get.
Here are the numbers, courtesy of @visionmobile, independent experts in developer economics.