My husband and I have been bitching about this for several years, because it really does seem to be a trend in movie-making right now. I am also not necessarily opposed to the idea of a re-make in general, but I think that to make it worthwhile, it has to either go in a completely different direction, or it has to be way better than the original. Honestly, in the case of Ocean's Eleven, the re-make is just an all-around better movie. Most of the time, though, that's not the case; and increasingly, we seem to be seeing shitty re-makes of shitty old movies. Like The Italian Job, previously mentioned. For example - The Stepford Wives? Why? Why the fuck, why? The original is okay - not earth-shattering, but okay. The re-make, despite several great cast members, was terrible. Why re-make a movie that's going to be shittier than the original? With Charlie and the Chocolate Factory, however - while I personally like the original Willy Wonka and the Chocolate Factory with Gene Wilder better - I understand that Tim Burton was going for a creepier, more fantastical, weird re-telling of the story, and I was interested to watch it, just to see the story a different way.
Our theory is that the public will finally revolt against re-makes when someone tries to do The Wizard of Oz, which of course, just cannot be done, and it's a movie that appeals to almost every person in the general population (ie, not a genre piece that most people don't care about).