The song has disappointed me for these reasons:
Chris Martin said that for this new album (something that must be different of the last "trilogy", as Martin called it) the Piano would be eliminated... But, surprise! The ending of Violet Hill sounds like other typical Coldplay songs (falsetto + piano). In addition of that, I can hear (and I'm sure you too) a piano during all the song.
I've be waiting for a new, modern or innovative sound, but this single is just the same as always (repeated formula). Violet Hill, I'm sure and I expect, it's not the best choise, from Viva la Vida, to be the first single.
And another thing: Chris Martin said also that falsettos would be eliminated. Well, as ocurred with the piano, I can hear the acute voice of Martin sometimes in the song.
The song is simple, with a "sticky" and easy riff. Maybe the distorted guitar is the only good and different thing.
I expect that the complete album will be different to their last discs.
VH is just a good and sticky song, not a masterpiece or the best song of Coldplay.