iOS 5.0 and higher allows you to stream audio or video signals from Aplle tablet of any generation that is from iPad / iPad 2 / iPad 3 / iPad 4 and iPad mini to remote device with relevant feature called AirPlay. This streaming may be either wireless or via an Apple HDMI or VGA connected cable. Owners of the original iPad may take advantage of AirPlay only by installing application/s specifically capable of this feature. The signature of such capability is the Airplay button found directly in the app interface.
Mind you, if you have the original iPad and developers have not written the specific app to support Airplay then you're out of business and cannot stream say music from your tablet directly to AirPlay-enabled speakers, but you are lucky if they have.
iPad 2 and the newest iPad 3 / iPad 4 & iPad mini perform AirPlay routine even more efficiently, as these Apple tablets allow to mirror output of any app. All of them have a default AirPlay switch along with volume controls on the multitasking dock.
Accessing AirPlay from any app is possible as long as your AirPlay - compatible devices are properly configured. To stream music / video from ether iPad 2 / ipad 3 or iPad 4 / iPad mini: