Flash is dead. Adobe has stated that they have given up on making a version that works on mobile devices. They have decided to embrace HTML5, and eventually all flash will be gone. There have been attempts to port it to the iPad, only to find that it was not a pleasant viewing experience. The Android tablets originally tried to beat Apple by providing Flash on their products, only to find customer disatisfaction.
You can watch videos on several sites. Netflix and Hulu + are just two of many. Some networks like ABC have their shows available fo view on the iPad.