Built around the idea that “email isn’t fun anymore,” Raindrop aims to be a sort of intelligent inbox filtering system that kicks minor messages and notifications to the sidelines while foregrounding messages from Mom and other important people you actually know. The idea is to make a people-centric communication tool that brings your various services together in one interface, instead of constantly playing a game of “find that browser tab” when you want to check up on a particular conversation or thread.
Excerpt from Mashable.
Wave and Raindrop, both working to leverage the existing email. Should be interesting.