The movies on the iPod are 320x240, TV resolutions are usually at a minimum 640x480, and the newer HDTVs are 1366x768. Or the really high end ones are 1920x1200.
You can do it, I believe it'll be blurry tho'. It's not like photos where they have the photo optimized for viewing on the iPod and a higher resolution one for TV.
Just look at it this way ... would blowing something up 200% make things blurry on your computer? Now stretch that to be the size of the TV.