Nothing and thats the problem. Its the same it was since it started (as far as how it functions is concerned). And if I were to guess[1] it is rapidly loosing whatever standing it had good old days. Its horrible, because it had a lot of potential for growth in to something really amazing. In the fast moving internet landscape, you have to evolve with everyone else in order to survive. Other than a facelift, nothing much changed with delicious.
Sure there are sites and services that survived without evolving, but they are exceptions not the norm.
Once awesome but dying sites/softwares: Myspace, Digg, IE
