From Apple Knowledge Base:
The new iTunes focuses on music, movies, TV shows, podcasts, and audiobooks. Apps for iPhone, iPad, and iPod touch are now exclusively available in the new App Store for iOS. And the new App Store makes it easy to get, update, and redownload apps—all without a Mac or PC.
In a way, iTunes the Application is becoming less complicated. There are some who uses iTunes to keep a copy of their iOS Apps, but I bet that majority of iPhone and iPad users don’t use iTunes to download iOS Apps.