12. The system of claim 11 , wherein the channel engine further comprises a historical analyzer to determine the historical trend by at least one of measuring an increase in a number of the content items for the first channel category, measuring an increase in a number of times that one of the content items is accessed and tracking an event.
11. A system for generating a stream of content for a plurality of channels, the system comprising: one or more processors; a model generation engine stored on a memory and executed by the one or more processors, the model generation engine for generating a model for a user comprising an interest of the user and prior interaction of the user with heterogeneous data sources; a content categorizer stored on the memory and coupled to the model generation engine, the content categorizer for categorizing content items received from the heterogeneous data sources by annotating each content item with a dynamic feature including an interestingness score; a channel engine coupled to the content categorizer, the channel engine for identifying a first channel category for the user based on a historical trend and the prior interaction of the user with the heterogeneous data sources, the historical trend including a change in a number of the content items categorized under the first channel category; a user interface engine coupled to the channel engine, the user interface engine for providing the user with a user interface for customizing the plurality of channels with a second channel category; and a scoring engine coupled to the model generation engine, the content categorizer, the channel engine and the user interface engine, the scoring engine for computing the interestingness score for each candidate content item received from the heterogeneous data sources by summing properties of each candidate content item over single-attribute properties using the model and based upon interestingness of each candidate content item to the user and an extent to which the candidate content item's popularity has increased within a geographic area associated with the user, receiving an input through the user interface specifying the second channel category, querying the content items based on the first channel category, the second channel category and at least one channel attribute, in response to the query, receiving candidate content items that include the first channel category, the second channel category and the at least one channel attribute and comparing the interestingness score for each candidate content item with a threshold for the first channel category and the second channel category to determine the candidate content items that have an interestingness score that exceeds the threshold, and generating the stream of content from the candidate content items that have an interestingness score that exceeds the threshold.