AppleTV supports Netflix, Vimeo, YouTube and some subscriptions sports type content for video.
No news/cable channel feeds as such.
It does not have a web browser.
Potentially if there are iPhone/iPad apps for some of these news feeds you want or they have iPhone/iPad compatbible web pages (non-Flash) you may be able to select the content on an iPhone/iPad and transmit it to AppleTV using Airplay.
Apparently next iOS version will allow ipad 2 to mirror its screen on teh TV via AppleTV so browsing web on iPad shows on TV.
Airplay is all very well but an extra cumbersome step in the process in my opinion not to mention the need for charged or power connected portable devices.