Wouldn't it be possible to stream a video online by using either a first-party or third-party video player. For example: 1) You find the link of the video you wanna see. 2) You open a multiple-format video playing app and give it the link (3.0 has copy and paste). 3) It locates the video and streams it into the player. ... well?
It doesn't always have to be youtube anyways, but will have to be h.264 based or quicktime based in order to play on the iDevices