Today is when becomes the standard for streaming video.  They are now offering users the option to view videos that were uploaded in 1080p in 1080p.  This is Awesome.  Just to let you see, there is a difference in resolution.  Just make sure you computer can handle the pixels.  Now let's see some examples.  Nothing shows off 1080p best like some anime.  Don't forget to choose 1080p under the HD tab.

UPDATE: Looks like 1080p tab is currently only available on the YouTube site.