I went to a private view of Tacita Dean's piece in the Turbine Hall on 22nd February with my friend, the novelist Emma Darwin, and I see she's just posted a piece about it on The History Girls Blog.
This is so much more eloquent and poetic than I could manage that I'm just going to tell you to go and read it. Not only because it's about how older technologies are being superseded by the new (and in publishing, that's just as true with eBooks supplanting paper and physical media), but because she uses it as a jumping-off point for a much broader perspective.
She recognises our place in a continuum where no matter what the current technology is, we as its users and creators gather to talk about and guide its future in the same way that the clergy and stonemasons in a cathedral would have gathered to discuss the continuing construction of their building in the fourteenth century. Their object would have been to make the best possible version of a building that they could, and a group of cinematographers and artists talking about film and its future are concerned in the end with making the best possible image they can, no matter what's behind the lens being used to capture it.
The event was called "A Celebration of Film" and we were guests of ARRI Media, Kodak, Fuji, the BSC, Panavision and various other industry bodies, our thanks to them for an unexpectedly enlightening evening.