I haven't got the Tyranid codex yet, so I don't know much about it.
But from what I can see, it's quite scary.
Kudos to the guy who made this.
I saw this over at Pink Tyrands anyway. His Tyranids are very nicely done, I like how the colours are done. Pink and grey, very good combination... Check out his blog for the tricked out painting.
The video made me laugh like mad though I understand the atmosphere of the movie is very different.