1. A system for adaptive notification delivery, the system comprising: a plurality of network-enabled devices associated with a user, each of the network-enabled devices having a respective agent module to determine if its associated network-enabled device is capable of rendering content associated with a notification message received thereby, to advertise its services and capabilities to at least one other respective agent module, to discover at least one other respective agent module, and to communicate information with at least one other respective agent module; and a notification service node to receive notification messages for the user from at least one Instant Messaging (IM) network and to forward each of the notification messages to a current device of the network-enabled devices; wherein for each of the notification messages, the respective agent module for the current device directs the current device to render content associated therewith if capable of same, and if incapable, negotiates with another one of the network-enabled devices to render the content.