In the graveyard of cultural artifacts, in between the opera and the novel, there lies a plot of grass reserved for the single- or multi-musician compilation of unified sonic work known affectionately as the album. Standing there with a shovel, ready to break the soil, is a young gravedigger named The Internet.
With the rise of mixtapes, downloadable music, and the like, listeners are no longer forced to break a $20 (and once a twenty is broken, it's gone) on an entire album. They can pay a buck on iTunes for the song they really bought the album for. Or they can download it illegally on a P2P server.
What's more, especially in hip-hop, but slowly working it's way into indie rock, is the culture of the mixtape. A mixtape is a kind of album, except it's a compilation culled from various different artists (sometimes across different genres). And in the realm of the mixtape, the person putting the mixtape together, usually the DJ, is king. Before songs go out on albums by hip hop artists, major labels test them on the training fields of the mixtape circuit.
All this, coupled with the reign of the iPod - and our increasing reliance on the shuffle mode, which is somehow not only artistically but existentially significant (for reasons I don't have the energy to expound upon) - seem to hail the death of the album as we know it.
But of course there's always another side to this. One might make the claim that albums, in response to the nature of our downloadable, bitrate-crazy music culture, are actually responding musically: with shorter albums, or more unified albums that weave a narrative throughout (Sufjan Stevens comes to mind).
And there is an afterlife of cultural production, where though it has outlived its immediate relevance (this might have been for the album, the 1960's-90's), it continues to be a fresh new ground for experimentation and novelty, as with its literary counterpart, the novel. So, it might be some consolation that beautiful flowers do tend to bloom in graveyards.