What album/single is the song "Imitation" from? And I'd also like the source that says that the song "Imitiation" is the OP for the F/SN movie.
edit: I don't think there will be a OP song for the F/SN movie, because most anime movies never have an OP like anime series do. However, the song "Imitation" is actually already released, which LonE and Nipponsei and most anime music uploaders completely missed (for shame). So here's the link to the album that contains the song "Imitation": http://theakiba.com/2009/12/27/ricordanza-fatestay-night-tv-song-collection/
At the end of the blog entry, you'll stumble upon a hotfile link. That's the one.