iGoogle started as a custom Google homepage that allowed you to add gadgets for weather, news, mail and more. "The goal of this initiative is to bring together Google functionality, and content from across the web, in ways that are useful to our users," explained Google in 2005.
Just like My Yahoo, Netvibes and other custom start pages, iGoogle became a dashboard that gathered your favorite content from the web. It was a simplified feed reader, a platform for mini-apps and games, a great homepage for your browser. Social networks and smartphones addressed most of these use cases and iGoogle's popularity declined.
Most likely, Google will promote Google+ as an iGoogle replacement, even though it lacks many of its features. Google+ apps, themes and maybe even a dashboard-like interface could fill iGoogle's void.
iGoogle is not the only Google product that will be discontinued. Google Mini, Google Talk Chatback and the Symbian Google Search app will no longer be available, while the videos uploaded to Google Video will be automatically be migrated to YouTube starting from next month. "Google Video stopped taking uploads in May 2009. Later this summer we'll be moving the remaining hosted content to YouTube. Google Video users have until August 20 to migrate, delete or download their content. We'll then move all remaining Google Video content to YouTube as private videos that users can access in the YouTube video manager," mentions Google. You can manage the videos uploaded to Google Video using this page.