Coldplay Copyright Infringement?

Guitarist Joe Satriani has asserted in a complaint filed on Thursday that substantial portions of his 2004 song "If I Could Fly" were copied by Coldplay in its song "Viva La Vida." Judge for yourself:

Of course, you can't really tell, from a comparison of the songs, whether or not there's been infringement; as in all copyright infringement cases, any similarities between the songs are not enough, standing alone, to constitute infringement (no matter how similar the two compositions might be), because the plaintiff has to prove not only that the songs are "substantially similar" to one another, but also that Coldplay actually copied from Satriani's song (i.e., that the similarities aren't due to coincidence, or independent development, or from both artists copying from some third source . . .).